Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Payables and Accruals [Abstract] Accrued Liabilities Schedule of Accrued Liabilities [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Business Combination, Contingent Consideration Arrangements, Change In Contingent Consideration Liability [Roll Forward] Business Combination, Contingent Consideration Arrangements, Change In Contingent Consideration Liability [Roll Forward] Business Combination, Contingent Consideration Arrangements, Change In Contingent Consideration Liability [Roll Forward] Balance, Beginning of Period Business Combination, Contingent Consideration, Liability Cash payments Business Combination, Contingent Consideration, Payment Of A Portion Of Potential Earn-Out Consideration Amount Business Combination, Contingent Consideration, Payment Of A Portion Of Potential Earn-Out Consideration Amount Changes in fair value Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Balance, End of Period Business Combinations [Abstract] Acquisitions Business Combination Disclosure [Text Block] Restructuring and Related Activities [Abstract] Restructuring Restructuring and Related Activities Disclosure [Text Block] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Accrued Expenses And Other Liabilities [Member] Accrued Liabilities [Member] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Contract Termination Costs [Member] Contract Termination [Member] Severance and Other Associated Costs [Member] Employee Severance [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring expense Restructuring Charges Restructuring liability Restructuring Reserve Compensation Related Costs [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Units (RSUs) [Member] Restricted Stock Units (RSUs) [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of Shares (in thousands) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Balance outstanding at December 31, 2015 Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number Awarded Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Released Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures Non-vested and outstanding at September 30, 2016 Expected to vest (shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Expected To Vest Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Expected To Vest Weighted Average Grant Date Fair Value (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Grant Date Fair Value [Abstract] [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Grant Date Fair Value [Abstract] [Roll Forward] Balance outstanding at December 31, 2015 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Awarded Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Released Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Non-vested and outstanding at September 30, 2016 Expected to vest (usd per share) Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Expected To Vest, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Expected To Vest, Weighted Average Grant Date Fair Value Aggregate Fair Value (in thousands) Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value [Roll Forward] Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value [Roll Forward] Non-vested and outstanding at September 30, 2016 Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value, Nonvested And Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value, Nonvested And Outstanding Expected to vest Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value, Expected To Vest Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Aggregate Intrinsic Value, Expected To Vest Property, Plant and Equipment [Abstract] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property Plant And Equipment By Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computer Equipment And Software [Member] Computer Equipment And Software [Member] Computer Equipment And Software [Member] Furniture, Equipment and Building Improvements [Member] Furniture Equipment And Building Improvements [Member] Furniture, Equipment and Building Improvements [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property plant and equipment gross Property, Plant and Equipment, Gross Less: accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total Property, Plant and Equipment, Net Decrease to depreciation expense Depreciation, Increase (Decrease) Due to Change in Estimate Depreciation, Increase (Decrease) Due to Change in Estimate Decrease to net loss Net Income (Loss) Attributable to Parent, Increase (Decrease) Due to Change in Accounting Estimate Net Income (Loss) Attributable to Parent, Increase (Decrease) Due to Change in Accounting Estimate Basic net (loss) income per common share (in dollars per share) Earnings Per Share, Basic, Increase (Decrease) Due to Change in Accounting Estimate Earnings Per Share, Basic, Increase (Decrease) Due to Change in Accounting Estimate Diluted net (loss) income per common share (in dollars per share) Earnings Per Share, Diluted, Increase (Decrease) Due to Change in Accounting Estimate Earnings Per Share, Diluted, Increase (Decrease) Due to Change in Accounting Estimate Earnings Per Share [Abstract] Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Synchronite, LLC [Member] Synchronite, LLC [Member] Synchronite, LLC [Member] Statement Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Business [Member] Business [Member] Business [Member]. Consumer [Member] Consumer [Member] Consumer [Member] Goodwill [Line Items] Goodwill [Line Items] Beginning Balance Goodwill Foreign exchange adjustment Goodwill, Foreign Currency Translation Gain (Loss) Ending Balance Revenue Recognition [Abstract] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Typical service agreements Service Agreement Term Service Agreement Term Typical service agreements termination notice period Termination Notice Period2 Termination Notice Period2 Schedule of Goodwill Schedule of Goodwill [Table Text Block] Summary of Intangible Assets Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stockholders' Equity Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Statement of Financial Position [Abstract] ASSETS Assets [Abstract] CURRENT ASSETS: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Cash held as collateral Restricted Cash and Cash Equivalents Accounts receivable, net of allowance for doubtful accounts of $1,742 and $1,184 as of September 30, 2016 and December 31, 2015, respectively Accounts Receivable, Net, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance, Current Total current assets Assets, Current Property and equipment, net Intangibles, net Intangible Assets, Net (Excluding Goodwill) Goodwill Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Other assets Other Assets, Noncurrent Total assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] CURRENT LIABILITIES: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses and other current liabilities Accrued Liabilities, Current Deferred revenue Deferred Revenue, Current Total current liabilities Liabilities, Current Other liabilities Other Liabilities, Noncurrent Deferred tax liability Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies STOCKHOLDERS’ EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Treasury stock Treasury Stock, Value Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders’ equity Liabilities and Equity Accounting Policies [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] General and administrative expense [Member] General and Administrative Expense [Member] Cost of revenue [Member] Cost of Sales [Member] Contact At Once! and Engage [Member] Contact At Once! and Engage [Member] Contact At Once! and Engage [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Commitments and Contingencies Disclosure [Abstract] Rental expense for operating leases Operating Leases Rent Expenses Operating Leases Rent Expenses Defined benefit plan employer matching contribution on first five percent of employee compensation Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Percentage of employees' eligible compensation for employer matching contribution Percentage Of Eligible Employee Compensation Percentage Of Eligible Employee Compensation Defined benefit plan employer contribution limit Defined Contribution Plan, Employer Discretionary Contribution Amount Defined benefit plan employer contribution vesting period Defined Benefit Plan Employers Contribution Of Vesting Period Defined Benefit Plan Employers Contribution of Vesting Period Defined benefit plan employer contribution Defined Benefit Plan, Contributions by Employer Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter Of Credit For Office Space [Member] Letter Of Credit For Office Space [Member] Letter Of Credit For Office Space [Member] Letter Of Credit For Security Deposit [Member] Letter Of Credit For Security Deposit [Member] Letter Of Credit For Security Deposit [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Line of Credit [Member] Line of Credit [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Letter of credit outstanding Long-term Line of Credit Accounts receivable, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Net Income (Loss) Per Share Earnings Per Share [Text Block] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] $1.79 - $6.32 [Member] Exercise Price Range One [Member] Exercise Price Range One [Member] $6.54 - $9.20 [Member] Exercise Price Range Two [Member] Exercise Price Range Two [Member] $9.24 - $9.34 [Member] Exercise Price Range Three [Member] Exercise Price Range Three [Member] $9.44 - $10.09 [Member] Exercise Price Range Four [Member] Exercise Price Range Four [Member] $10.13 - $10.13 [Member] Exercise Price Range Five [Member] Exercise Price Range Five [Member] $10.31 - $12.32 [Member] Exercise Price Range Six [Member] Exercise Price Range Six [Member] $12.46 - $13.28 [Member] Exercise Price Range Seven [Member] Exercise Price Range Seven [Member] $13.34 - $16.98 [Member] Exercise Price Range Eight [Member] Exercise Price Range Eight [Member] $17.88 - $18.09 [Member] Exercise Price Range Nine [Member] Exercise Price Range Nine [Member] $18.24 - $18.24 [Member] Exercise Price Range Ten [Member] Exercise Price Range Ten [Member] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Exercise price range, minimum (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Exercise price range, maximum (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Options outstanding, Number of shares outstanding Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Options outstanding, Weighted-average remaining contractual life Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term Options outstanding, Weighted-average exercise price (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Options exercisable, Number of shares Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options Options exercisable, Weighted-average exercise price (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Summary of Property and Equipment Property, Plant and Equipment [Table Text Block] 2016 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Five Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Total Finite-Lived Intangible Assets, Net Segment Reporting [Abstract] Summary of Financial Information by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenues Attributable to Domestic and Foreign Operations Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block] Long-Lived Assets by Geographic Region Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block] Long Lived Assets By Geographic Region Long-lived Assets by Geographic Areas [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Statement Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Geographical [Domain] United States [Member] UNITED STATES Other Americas [Member] Other Americas [Member] Other Americas [Member] Americas [Member] Americas [Member] EMEA [Member] EMEA [Member] APAC [Member] POSIT - ASIA PACIFIC [Member] United Kingdom [Member] UNITED KINGDOM Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Revenue Revenues Payroll and other employee related costs Employee-related Liabilities, Current Professional services and consulting and other vendor fees Accrued Professional Fees, Current Sales commissions Accrued Sales Commission, Current Contingent earnout (see Notes 8 and 9) Contingent Earnout Liability Contingent earnout liability. Other Other Accrued Liabilities, Current Total Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected life Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Historical volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Restricted cash balance Asset Class [Axis] Asset Class [Axis] Fair Value by Asset Class [Domain] Asset Class [Domain] Money Market Funds [Member] Money Market Funds [Member] Foreign currency derivative contracts [Member] Foreign Exchange Forward [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Contingent Earn-Out [Member] Contingent Earn-Out [Member] Contingent Earn-Out [Member] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Assets Assets, Fair Value Disclosure Liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Schedule of Business Acquisitions, by Acquisition [Table] Engage Pty Limited [Member] Engage Pty Limited [Member] Engage Pty Limited [Member]. Contact At Once! [Member] Contact At Once! [Member] Contact At Once! [Member] Business acquisition, acquisition date Business Acquisition, Effective Date of Acquisition Total consideration transferred Business Combination, Consideration Transferred Acquisition costs incurred to acquire entity Business Combination, Acquisition Related Costs Assets acquired liabilities assumed, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Potential earn-out consideration Change in fair value of contingent consideration Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Payments for previous acquisition Payments for Previous Acquisition Cash payment Payments to Acquire Businesses, Gross Consideration transferred (in shares) Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Revenue Recognition Revenue Recognition [Text Block] Revenue Recognition [Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Sales and marketing expense [Member] Selling and Marketing Expense [Member] Product development expense [Member] Research and Development Expense [Member] Statement [Line Items] Statement [Line Items] Costs and expenses Costs and Expenses [Abstract] Cost of revenue Cost of Revenue Sales and marketing Selling and Marketing Expense General and administrative General and Administrative Expense Product development Research and Development Expense Restructuring costs Amortization of purchased intangibles Amortization of Intangible Assets Total costs and expenses Costs and Expenses (Loss) income from operations Operating Income (Loss) Other expense Nonoperating Income (Expense) (Loss) income before provision for (benefit from) income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Provision for (benefit from) income taxes Income Tax Expense (Benefit) Net (loss) income Net Income (Loss) Attributable to Parent Basic net (loss) income per common share (in dollars per share) Earnings Per Share, Basic Diluted net (loss) income per common share (in dollars per share) Earnings Per Share, Diluted Weighted average shares outstanding used in basic net (loss) income per common share calculation (in shares) Weighted Average Number of Shares Outstanding, Basic Weighted average shares outstanding used in diluted net (loss) income per common share calculation (in shares) Weighted Average Number of Shares Outstanding, Diluted Stock compensation expense Share-based Compensation Depreciation expense Depreciation, Nonproduction Property and Equipment Property, Plant and Equipment Disclosure [Text Block] Accrued Liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Legal Matters Legal Matters and Contingencies [Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Corporate [Member] Corporate, Non-Segment [Member] Revenue Segment Reporting Information, Revenue for Reportable Segment [Abstract] Hosted services – Business Business Services Revenue Business Services Revenue Hosted services – Consumer Consumer Services Revenue Consumer Services Revenue Professional services Professional Services Revenue Professional Services Revenue Revenue Sales and marketing Unallocated corporate expenses Segment Reporting Unallocated Corporate Expenses Segment Reporting Unallocated Corporate Expenses Operating income (loss) Statement of Cash Flows [Abstract] OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net (loss) income Adjustments to reconcile net loss to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Stock-based compensation expense Depreciation Depreciation Amortization of purchased intangibles Amortization Deferred income taxes and other non-cash tax items Deferred Income Tax Expense (Benefit) Change in fair value contingent consideration Provision for doubtful accounts, net Provision for Doubtful Accounts Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Prepaid expenses and other current assets Increase Decrease In Prepaid Expense And Other Current Assets Increase (Decrease) In Prepaid Expense And Other Current Assets Other assets Increase (Decrease) in Other Operating Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued expenses and other current liabilities Increase (Decrease) in Accrued Liabilities Deferred revenue Increase (Decrease) in Deferred Revenue Other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of property and equipment, including capitalized software Payments to Acquire Productive Assets Cash held as collateral for foreign exchange forward contracts Increase (Decrease) in Restricted Cash Payments for acquisitions and intangible assets, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Excess tax benefit from the exercise of employee stock options Excess Tax Benefit from Share-based Compensation, Financing Activities Proceeds from issuance of common stock in connection with the exercise of options Proceeds from Issuance of Common Stock Payments related to contingent consideration Payments of Merger Related Costs, Financing Activities Repurchase of common stock Payments for Repurchase of Common Stock Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities EFFECT OF FOREIGN EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS Effect of Exchange Rate on Cash and Cash Equivalents CHANGE IN CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, Period Increase (Decrease) CASH AND CASH EQUIVALENTS - Beginning of the period CASH AND CASH EQUIVALENTS - End of the period SUPPLEMENTAL DISCLOSURE OF OTHER CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] Cash paid for income taxes Income Taxes Paid, Net SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Purchase of property and equipment recorded in accounts payable Capital Expenditures Incurred but Not yet Paid Leasehold improvements funded by landlord Noncash or Part Noncash Acquisition, Costs Noncash or Part Noncash Acquisition, Costs Israel [Member] ISRAEL Australia [Member] AUSTRALIA Netherlands [Member] NETHERLANDS Other [Member] Total long-lived assets Assets, Noncurrent Weighted Average Assumptions of Fair Value Options Using Black-Scholes Option-Pricing Model Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary of Stock Option Activity and Weighted Average Exercise Prices Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of Status of Nonvested Shares Schedule of Nonvested Share Activity [Table Text Block] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block] Number of operating segments Number of Operating Segments Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2012 Stock Repurchase Program [Member] 2012 Stock Repurchase Program [Member] 2012 Stock Repurchase Program [Member] Period Reported [Axis] Period Reported [Axis] Period Reported [Axis] Period Reported [Domain] Period Reported [Domain] Period Reported [Domain] 2009 Plan [Member] Amended [Member] Amended [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 1998 Plan [Member] Nineteen Ninety Eight Plan [Member] Nineteen Ninety Eight Plan [Member] 2000 Plan [Member] Two Thousand Plan [Member] Two Thousand Plan [Member] 1998 and 2000 Plan [Member] Nineteen Ninety Eight And Two Thousand Plan [Member] Nineteen Ninety Eight and Two Thousand Plan [Member] 2009 Plan [Member] Two Thousand Nine Plan [Member] Two Thousand Nine Plan [Member] 2010 Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan Twenty Ten [Member] Employee Stock Purchase Plan, 2010 [Member] Award Type [Domain] Incentive Stock Option [Member] Incentive Stock Option [Member] Incentive Stock Option [Member] Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Shares repurchased (in shares) Treasury Stock, Shares Stock repurchase program, remaining authorized repurchase amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Per share weighed average fair value of stock options granted during the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Period used to determine volatility Share-based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Period Used To Determine Volatility Share-based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Period Used To Determine Volatility Shares of common stock available for issuance (up to) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Increase in number of shares of common stock available for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Stock option term Share Based Compensation Arrangement By Share Based Payment Award Options Expiration Term Share Based Compensation Arrangement by Share Based Payment Award, Options, Expiration Term Total value of stock options exercised Stock Issued During Period, Value, Stock Options Exercised Unrecognized compensation cost related to nonvested share-based compensation arrangements Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Weighted average recognition period of unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Effect of option to purchase share of common stock on diluted net income per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Period Increase (Decrease), Weighted Average Exercise Price Description of Business and Basis of Presentation Business Description and Accounting Policies [Text Block] Statement of Comprehensive Income [Abstract] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Aggregate amortization expense for intangible assets Fair Value Measurements Fair Value Disclosures [Text Block] Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Options outstanding, beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Options granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Options cancelled or expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Options outstanding, ending balance (in shares) Options vested and expected to vest (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Options exercisable at September 30, 2016 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Options outstanding, beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Options granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Options exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Options cancelled or expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Options outstanding, ending balance (in dollars per share) Options vested and expected to vest (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Options exercisable at September 30, 2016 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Options outstanding at September 30, 2016 Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Options exercisable at September 30, 2016 Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract] Options outstanding at September 30, 2016 Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Options vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Options exercisable at September 30, 2016 Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Basic Effect of assumed exercised options Weighted Average Number Diluted Shares Outstanding Adjustment Diluted Restructuring and Related Costs Restructuring and Related Costs [Table Text Block] Document - Document And Entity Information [Abstract] Document - Document and Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Segment Information Segment Reporting Disclosure [Text Block] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Finite Lived Intangible Assets By Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Technology [Member] Technology [Member] Technology [Member] Customer relationships [Member] Customer Contracts [Member] Trade names [Member] Trade Names [Member] Non-compete agreements [Member] Noncompete Agreements [Member] Patents [Member] Patents [Member] Other [Member] Other Intangible Assets [Member] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Finite-lived Intangible Assets Acquired Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Amount Weighted Average Amortization Period Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Fair Value, Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Change in Fair Value of Level 3 Liabilities Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Schedule of Derivative Liabilities at Fair Value Schedule of Derivative Liabilities at Fair Value [Table Text Block] Gain (Losses) on Derivative Instruments Recognized in Income Statement Derivative Instruments, Gain (Loss) [Table Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Derivative [Table] Derivative [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Foreign Currency Derivatives Contracts [Member] Foreign Exchange Contract [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Prepaid Expenses and Other Current Assets [Member] Prepaid Expenses and Other Current Assets [Member] Other Expense [Member] Other Expense [Member] Derivative [Line Items] Derivative [Line Items] Notional amount Derivative, Notional Amount Fair value Derivative, Fair Value, Net Derivative assets Derivative Asset Derivative liabilities Derivative Liability Gain (losses) on Derivative Instruments Recognized in Statements of Operations Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Summary of Operations Summary Of Operations [Policy Text Block] The accounting policy related to summary of operations. Basis of Presentation Unaudited Condensed Consolidated Financial Information [Policy Text Block] The accounting policy related to the unaudited condensed consolidated financial information. Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Net Income (Loss) Per Share Earnings Per Share, Policy [Policy Text Block] Segment Information Segment Reporting, Policy [Policy Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Stock-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]