Ellie Mae (ELLI) 10-Q 9 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 01, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ELLIE MAE INC
Entity Central Index Key	1,122,388
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		34,536,251

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 246,832	$ 380,907
Short-term investments	119,327	41,841
Accounts receivable, net of allowance for doubtful accounts of $270 and $45 as of September 30, 2017 and December 31, 2016, respectively	48,987	39,358
Prepaid expenses and other current assets	17,324	15,209
Total current assets	432,470	477,315
Property and equipment, net	166,864	126,297
Long-term investments	112,874	45,931
Intangible assets, net	14,056	17,289
Deposits and other assets	18,132	10,138
Goodwill	74,547	74,547
Total assets	818,943	751,517
Current liabilities:
Accounts payable	14,537	15,942
Accrued and other current liabilities	21,121	39,809
Deferred revenue	20,322	23,126
Total current liabilities	55,980	78,877
Other long-term liabilities	16,316	17,732
Total liabilities	72,296	96,609
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $0.0001 par value per share; 140,000,000 authorized shares, 34,526,383 and 33,685,649 shares issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	3	3
Additional paid-in capital	646,343	612,098
Accumulated other comprehensive loss	(211)	(219)
Retained earnings	100,512	43,026
Total stockholders' equity	746,647	654,908
Total liabilities and stockholders' equity	$ 818,943	$ 751,517

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowances for doubtful accounts	$ 270	$ 45
Common stock, par value (in usd per share)	$ 0.0001000	$ 0.0001000
Common stock, shares authorized	140,000,000	140,000,000
Common stock, shares issued	34,526,383	33,685,649
Common stock, shares outstanding	34,526,383	33,685,649

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Revenues	$ 107,029	$ 100,381	$ 304,156	$ 264,104
Cost of revenues	39,603	32,218	112,638	87,302
Gross profit	67,426	68,163	191,518	176,802
Operating expenses:
Sales and marketing	13,522	12,654	46,762	40,446
Research and development	15,901	15,081	49,354	42,196
General and administrative	20,159	19,360	55,828	52,885
Total operating expenses	49,582	47,095	151,944	135,527
Income from operations	17,844	21,068	39,574	41,275
Other income, net	1,140	204	2,403	565
Income before income taxes	18,984	21,272	41,977	41,840
Income tax provision (benefit)	4,465	7,492	(964)	14,966
Net income	$ 14,519	$ 13,780	$ 42,941	$ 26,874
Net income per share of common stock:
Basic (in usd per share)	$ 0.42	$ 0.43	$ 1.26	$ 0.88
Diluted (in usd per share)	$ 0.41	$ 0.41	$ 1.20	$ 0.84
Weighted average common shares used in computing net income per share of common stock:
Basic (shares)	34,275,116	31,916,910	34,004,025	30,407,020
Diluted (shares)	35,784,972	33,482,533	35,803,817	32,039,083
Other comprehensive income, net of taxes:
Net income	$ 14,519	$ 13,780	$ 42,941	$ 26,874
Unrealized gain (loss) on investments	53	(107)	8	322
Comprehensive income	$ 14,572	$ 13,673	$ 42,949	$ 27,196

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 42,941	$ 26,874
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	26,024	14,487
Amortization of intangible assets	3,233	4,442
Stock-based compensation expense	25,260	23,456
Deferred income taxes	(1,259)	9,363
Loss on disposal of property and equipment	0	5
Amortization (accretion) of investments	(948)	779
Changes in operating assets and liabilities:
Accounts receivable, net	(9,628)	(19,267)
Prepaid expenses and other current assets	(2,115)	(1,381)
Deposits and other assets	508	(2,298)
Accounts payable	625	(349)
Accrued, other current and other liabilities	(12,271)	1,238
Deferred revenue	(2,749)	3,759
Net cash provided by operating activities	69,621	61,108
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property and equipment	(24,919)	(21,074)
Acquisition of internal-use software	(40,047)	(25,218)
Purchases of investments	(213,749)	(49,201)
Maturities of investments	70,276	45,494
Sale of investments	0	20,000
Net cash used in investing activities	(208,439)	(29,999)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of capital lease obligations	(587)	(2,954)
Proceeds from issuance of common stock under employee stock plans	17,590	15,339
Proceeds (payment of issuance costs) relating to common stock issued in public offering	(15)
Proceeds (payment of issuance costs) relating to common stock issued in public offering		271,411
Tax payments related to shares withheld for vested restricted stock units	(12,245)	(4,762)
Net cash provided by financing activities	4,743	279,034
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(134,075)	310,143
CASH AND CASH EQUIVALENTS, Beginning of period	380,907	34,396
CASH AND CASH EQUIVALENTS, End of period	246,832	344,539
Supplemental disclosure of cash flow information:
Cash paid for interest	431	213
Cash paid for (refunded from) income taxes	(1,292)	218
Supplemental disclosure of non-cash investing and financing activities:
Fixed asset purchases accrued but not paid	3,930	1,196
Stock-based compensation capitalized to property and equipment	$ 3,640	$ 1,927

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Ellie Mae, Inc. (“Ellie Mae,” the “Company,” “we,” “our,” or “us”) is a leading provider of innovative on-demand software solutions and services for the residential mortgage industry in the United States . Banks, credit unions, and mortgage lenders use the Company’s Encompass® all-in-one mortgage management solution (“Encompass”) to originate and fund mortgages and improve compliance, loan quality, and efficiency.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“ U.S. GAAP ”) and applicable rules and regulations of the Securities and Exchange Commission (“ SEC ”) regarding interim financial reporting. Certain information and note disclosures included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 , which was filed with the SEC on February 22, 2017 (“ 2016 Form 10-K ”). The condensed consolidated balance sheet as of December 31, 2016 , included herein, was derived from the audited financial statements as of that date but does not include all disclosures, including notes, required by U.S. GAAP . In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, and cash flows for the interim periods but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending December 31, 2017 or any future period. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management evaluates estimates on a regular basis including those relating to revenue recognition, allowance for doubtful accounts, goodwill, intangible assets, valuation of deferred income taxes, stock-based compensation, and unrecognized tax benefits, among others. Actual results could differ from those estimates, and such differences may have a material impact on the Company’s condensed consolidated financial statements and footnotes. Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements in its 2016 Form 10-K . There have been no significant changes to these policies during the nine months ended September 30, 2017 , except in relation to the Company’s adoption of ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Shared-Based Payment Accounting (“ASU 2016-09”) on January 1, 2017, whereby the Company now records excess tax benefits and tax deficiencies as an income tax benefit or expense when stock awards vest or settle, and the Company no longer classifies the cash flow from excess tax benefits as a reduction from operating cash flows. The Company elected provisions of the standard permitting retrospective restatement of prior period amounts presented in the statement of cash flows related to these transactions. This resulted in a $5.5 million increase in net cash provided by operating activities and a corresponding $5.5 million decrease in net cash provided by financing activities for the nine months ended September 30, 2016 from previously reported amounts. Comprehensive Income Comprehensive income consists of net income and other comprehensive income . Other comprehensive income includes certain changes in equity that are excluded from net income, specifically unrealized gains on marketable securities. Except for net realized gain on investments , which was not significant, there were no reclassifications out of accumulated other comprehensive income that affected net income during the three and nine months ended September 30, 2017 and 2016 . Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“ FASB ”) issued Accounting Standards Update (“ ASU ”) No. 2014-09, Revenue from Contracts with Customers (“ ASU 2014-09 ”), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This standard also requires significantly expanded disclosures about revenue recognition. The effective date for public entities is fiscal years beginning after December 15, 2017 and early adoption is allowed. The Company will adopt the new standard as of January 1, 2018. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (modified retrospective method). The Company currently anticipates adopting the standard using the modified retrospective method and is continuing to evaluate the impact of the new standard on its accounting policies, processes, and systems, including impacts from guidance issued by the FASB Transition Resource Group. The Company has assigned internal resources, engaged a third-party service provider, and is in the process of updating its systems and continuing the evaluation of the quantitative impact to our financial statements. The Company expects an impact to its Encompass subscription and professional services revenue streams due to the removal of the current limitation on contingent revenue, which may affect the timing and allocation of revenues being recognized for certain contracts. The Company has also identified potential impacts to the costs to obtain contracts, which is primarily comprised of sales commissions and the related fringe benefits associated with non-cancelable contracts. The Company expects to capitalize certain costs that are expensed under the current standard, and the Company expects an increase in the amortization period over which the capitalized costs will be recognized and is continuing to evaluate the impact to the expected period of benefit under ASU 2014-09. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to put most leases on their balance sheets but recognize the expenses on their income statements in a manner similar to current practice. ASU 2016-02 states that a lessee would recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. The standard is effective for interim and annual periods beginning after December 15, 2018, and early adoption is permitted. The Company currently does not intend to early adopt and is evaluating the impact of this accounting standard update on its consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), which provides guidance on determining which changes to the terms and conditions of share-based payment awards require an entity to apply modification accounting under Topic 718. ASU 2017-09 is effective for interim and annual periods beginning after December 15, 2017, and early adoption is permitted. The Company is currently evaluating the timing of adoption and does not expect the adoption of the accounting standard update to have a material impact on its consolidated financial statements.

Net Income Per Share of Common

Net Income Per Share of Common Stock	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Net Income Per Share of Common Stock	Net Income Per Share of Common Stock Net income per share of common stock is calculated by dividing net income by the weighted average shares of common stock outstanding during the period. Diluted net income per share of common stock is calculated by dividing net income by the weighted average shares of common stock outstanding and potential shares of common stock during the period. Potential shares of common stock include dilutive shares attributable to the assumed exercise of stock options, restricted stock unit awards (“ RSU s”), performance-vesting RSUs, performance share awards (“ Performance Awards ”), and Employee Stock Purchase Plan (“ ESPP ”) shares using the treasury stock method, if dilutive. The components of net income per share of common stock were as follows: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (in thousands, except share and per share amounts) Net income $ 14,519 $ 13,780 $ 42,941 $ 26,874 Basic shares: Weighted average common shares outstanding 34,275,116 31,916,910 34,004,025 30,407,020 Diluted shares: Weighted average shares used to compute basic net income per share 34,275,116 31,916,910 34,004,025 30,407,020 Effect of potentially dilutive securities: Employee stock options, RSUs, performance-vesting RSUs, Performance Awards and ESPP shares 1,509,856 1,565,623 1,799,792 1,632,063 Weighted average shares used to compute diluted net income per share 35,784,972 33,482,533 35,803,817 32,039,083 Net income per share: Basic $ 0.42 $ 0.43 $ 1.26 $ 0.88 Diluted $ 0.41 $ 0.41 $ 1.20 $ 0.84 The following potential weighted average common shares were excluded from the computation of diluted net income per share, as their effect would have been anti-dilutive: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 Employee stock options and awards 319,922 — 179,091 42,036 Performance-vesting RSUs and Performance Awards are included in the diluted shares outstanding for each period if the established performance criteria have been met at the end of the respective periods. However, if none of the required performance criteria have been met for such awards, the Company includes the number of shares that would be issuable if the end of the reporting period were the end of the contingency period. Accordingly, in addition to the employee stock options and awards noted above, 59,455 and 167,336 shares underlying performance-vesting RSUs and Performance Awards were excluded from the dilutive shares outstanding for each of the three and nine months ended September 30, 2017 and 2016 , respectively.

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Financial Instruments and Fair Value Measurements [Abstract]
Financial Instruments and Fair Value Measurements	Financial Instruments and Fair Value Measurements Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are classified and disclosed in one of the following three categories: Level 1 — Valuations based on quoted prices in active markets for identical assets or liabilities. Level 2 — Valuations based on other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Valuations based on inputs that are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the assets or liabilities. The following tables set forth by level within the fair value hierarchy the Company’s financial assets that were accounted for at fair value on a recurring basis: September 30, 2017 December 31, 2016 Level 1 Level 2 Total Level 1 Level 2 Total (in thousands) (in thousands) Cash equivalents: Money market funds $ 4,363 $ — $ 4,363 $ 2,733 $ — $ 2,733 Corporate notes and obligations — 17,327 17,327 — — — U.S. government and government agency obligations 6,575 14,829 21,404 151,660 149,976 301,636 Investments: Certificates of deposit — 8,140 8,140 — 12,088 12,088 Corporate notes and obligations — 73,713 73,713 — 28,892 28,892 Municipal obligations — 10,475 10,475 — 11,361 11,361 U.S. government and government agency obligations 51,021 88,852 139,873 4,579 30,852 35,431 $ 61,959 $ 213,336 $ 275,295 $ 158,972 $ 233,169 $ 392,141 The Company classifies its money market funds that are specifically backed by debt securities and U.S. government obligations as Level 1 instruments, due to the use of observable market prices for identical securities that are traded in active markets . Valuation of the Company’s marketable securities investments classified as Level 2 is achieved primarily through broker quotes when such investments exist in a non-active market. At September 30, 2017 and December 31, 2016 , the Company did not have any assets or liabilities that were valued using Level 3 inputs. For the three and nine months ended September 30, 2017 and 2016 , there were no transfers of financial instruments between the levels. Realized gains and losses from the sale of investments were not significant during the three and nine months ended September 30, 2017 and 2016 . The carrying amounts, gross unrealized gains and losses and estimated fair value of cash and cash equivalents and both short-term and long-term investments consisted of the following: September 30, 2017 December 31, 2016 Amortized Cost Unrealized Gains Unrealized Losses Carrying or Fair Value Amortized Unrealized Gains Unrealized Losses Carrying or (in thousands) (in thousands) Cash and cash equivalents: Cash $ 203,738 $ — $ — $ 203,738 $ 76,538 $ — $ — $ 76,538 Money market funds 4,363 — — 4,363 2,733 — — 2,733 Corporate notes and obligations 17,327 — — 17,327 — — — — U.S. government and government agency obligations 21,403 1 — 21,404 301,631 8 (3 ) 301,636 $ 246,831 $ 1 $ — $ 246,832 $ 380,902 $ 8 $ (3 ) $ 380,907 Investments: Corporate notes and obligations $ 73,754 $ 26 $ (67 ) $ 73,713 $ 28,978 $ 1 $ (87 ) $ 28,892 Certificates of deposit 8,138 3 (1 ) 8,140 12,094 13 (19 ) 12,088 Municipal obligations 10,471 11 (7 ) 10,475 11,422 1 (62 ) 11,361 U.S. government and government agency obligations 140,050 2 (179 ) 139,873 35,502 8 (79 ) 35,431 $ 232,413 $ 42 $ (254 ) $ 232,201 $ 87,996 $ 23 $ (247 ) $ 87,772 The following table shows the gross unrealized losses and the related fair values of the Company’s investments that have been in a continuous unrealized loss position. The Company did not identify any investments as other-than-temporarily impaired at September 30, 2017 or December 31, 2016 based on its evaluation of available evidence, such as the Company’s intent to hold and whether it is more likely than not that the Company will be required to sell the investment before recovery of the investment’s amortized basis. The Company expects to receive the full principal and interest on these investments. September 30, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Corporate notes and obligations $ 31,732 $ (32 ) $ 7,710 $ (35 ) $ 39,442 $ (67 ) Certificates of deposit 2,452 — 245 (1 ) 2,697 (1 ) U.S. government, government agency, and municipal obligations 124,336 (154 ) 5,500 (32 ) 129,836 (186 ) $ 158,520 $ (186 ) $ 13,455 $ (68 ) $ 171,975 $ (254 ) December 31, 2016 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Corporate notes and obligations $ 26,076 $ (87 ) $ — $ — $ 26,076 $ (87 ) Certificates of deposit 5,651 (19 ) — — 5,651 (19 ) U.S. government, government agency, and municipal obligations 180,138 (144 ) 385 — 180,523 (144 ) $ 211,865 $ (250 ) $ 385 $ — $ 212,250 $ (250 ) The following table summarizes the maturities of the Company’s investments at September 30, 2017 : Carrying or Fair Value (in thousands) Remainder of 2017 $ 28,276 2018 102,878 2019 72,308 2020 28,739 Total $ 232,201 Actual maturities may differ from the contractual maturities because borrowers may have the right to call or prepay certain obligations.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2017
Statement of Financial Position [Abstract]
Balance Sheet Components	Balance Sheet Components Property and Equipment, net Property and equipment, net, consisted of the following: September 30, December 31, 2017 2016 (in thousands) Computer equipment and software (1) (2) $ 66,871 $ 54,029 Internal-use software (2) 96,022 62,573 Furniture and fixtures 9,218 6,838 Leasehold improvements 29,389 18,532 Property and equipment 201,500 141,972 Accumulated depreciation and amortization (1) (75,015 ) (48,991 ) Subtotal 126,485 92,981 Internal-use software and other assets not placed in service 40,379 33,316 Property and equipment, net $ 166,864 $ 126,297 ________________ (1) Includes computer equipment and software under capital leases (2) Certain reclassifications of prior period amounts have been made to conform to the current period presentation, such reclassification did not materially change previously reported consolidated financial statements. Computer equipment and software under capital leases, net, consisted of the following: September 30, December 31, 2017 2016 (in thousands) Computer equipment $ 8,715 $ 8,715 Software 1,517 1,517 Accumulated depreciation and amortization (8,676 ) (6,522 ) Net computer equipment and software under capital leases $ 1,556 $ 3,710 Depreciation and amortization expense for the three and nine months ended September 30, 2017 was $9.7 million and $26.0 million , respectively. Depreciation and amortization expense for the three and nine months ended September 30, 2016 was $5.8 million and $14.5 million , respectively. Depreciation and amortization of assets under capital leases which is included in the depreciation and amortization expense for the three and nine months ended September 30, 2017 was $0.6 million and $2.2 million , respectively. Depreciation and amortization of assets under capital leases which is included in depreciation and amortization expense for the three and nine months ended September 30, 2016 was $0.8 million and $2.4 million , respectively. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following: September 30, December 31, 2017 2016 (in thousands) Accrued payroll and related expenses $ 15,281 $ 31,848 Accrued commissions 643 1,832 Accrued royalties 1,828 1,395 Sales and other taxes 1,298 2,327 Other accrued liabilities (1) 2,071 2,407 $ 21,121 $ 39,809 ________________ (1) Certain reclassifications of prior period amounts have been made to conform to the current period presentation, such reclassification did not materially change previously reported consolidated financial statements.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Net	Goodwill and Intangible Assets, Net The carrying value of goodwill at September 30, 2017 was $74.5 million . There were no changes in the carrying value of goodwill during the three and nine months ended September 30, 2017 . Intangible assets, net, consisted of the following: September 30, 2017 Gross Carrying Accumulated Net Intangibles Weighted Average Remaining Useful Life (in thousands) (in years) Assets subject to amortization: Developed technology $ 11,535 $ (9,181 ) $ 2,354 2.1 Trade names 331 (331 ) — 0.0 Customer relationships 19,400 (11,928 ) 7,472 3.4 Order backlog 370 (179 ) 191 2.1 Total assets subject to amortization: 31,636 (21,619 ) 10,017 3.1 Assets not subject to amortization: Trade name 4,039 — 4,039 $ 35,675 $ (21,619 ) $ 14,056 December 31, 2016 Gross Carrying Accumulated Net Intangibles Weighted Average Remaining Useful Life (in thousands) (in years) Assets subject to amortization: Developed technology $ 11,535 $ (8,183 ) $ 3,352 2.7 Trade names 331 (331 ) — 0.0 Customer relationships 19,400 (9,762 ) 9,638 4.0 Order backlog 370 (110 ) 260 2.8 Total assets subject to amortization: 31,636 (18,386 ) 13,250 3.6 Assets not subject to amortization: Trade name 4,039 — 4,039 $ 35,675 $ (18,386 ) $ 17,289 Amortization expense associated with intangible assets for the three and nine months ended September 30, 2017 was $1.1 million and $3.2 million , respectively. Amortization expense associated with intangible assets for the three and nine months ended September 30, 2016 was $1.5 million and $4.4 million , respectively. Future amortization expense for intangible assets at September 30, 2017 was as follows: Amortization (in thousands) Remainder of 2017 $ 1,061 2018 3,443 2019 3,166 2020 1,778 2021 314 2022 255 $ 10,017

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company computes its interim provision for income taxes by applying the estimated annual effective tax rate to the year-to-date income from recurring operations and adjusts the provision for discrete tax items recorded in the period. The Company evaluates and updates its estimated annual effective income tax rate on a quarterly basis. The estimated annual effective tax rate as of September 30, 2017 and 2016 was 35.9% and 36.5% , respectively. Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (dollars in thousands) (dollars in thousands) Income tax provision (benefit) $ 4,465 $ 7,492 $ (964 ) $ 14,966 Effective tax rate (1) 23.5 % 35.2 % (2.3 )% 35.8 % ________________ (1) The impact to the effective tax rate due to the excess tax benefits of stock-based compensation from the adoption of ASU 2016-09 was 12.0% and 37.0% for the three and nine months ended September 30, 2017 , respectively. The Company’s effective tax rate was 23.5% and (2.3)% for the three and nine months ended September 30, 2017 , which was lower than the U.S. federal statutory rate of 35% . The lower tax rate was primarily due to the discrete impact of excess tax benefits of stock-based compensation from the adoption of ASU 2016-09 and the federal R&D credit, partially offset by the non-deductible stock-based compensation. As described in Note 2 “Basis of Presentation and Significant Accounting Policies”, the Company adopted ASU 2016-09 on January 1, 2017, which requires the excess tax benefits or deficiencies to be reflected in the Consolidated Statements of Comprehensive Income as a component of the provision for income taxes, which were previously recognized in equity. Total excess tax benefits recognized for the three and nine months ended September 30, 2017 was $2.3 million and $15.5 million , respectively. The Company’s tax positions are subject to income tax audits by multiple tax jurisdictions. The Company accounts for uncertain tax positions and believes that it has provided adequate reserves for its unrecognized tax benefits for all tax years still open for assessment. The Company also believes that it does not have any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within the next twelve months. The Company has a policy to classify accrued interest and penalties associated with uncertain tax positions together with the related liability in the balance sheet, and to include the expenses incurred related to such accruals in the provision for income taxes. There were no interest or penalties included in the provision for income taxes during the nine months ended September 30, 2017 and 2016 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases As of September 30, 2017 , the Company leased eight facilities under operating lease arrangements. The lease expiration dates range from September 2019 to December 2025 . Certain leases contain escalation clauses calling for increased rents. The Company recognizes rent expense on a straight-line basis over the lease period and has recorded deferred rent for the difference between rent payments and rent expense recognized. Legal Proceedings From time to time, the Company is involved in litigation that it believes is of the type common to companies engaged in the Company’s line of business, including commercial and employment disputes. As of the date of this Quarterly Report on Form 10-Q, the Company is not involved in any pending legal proceedings whose outcome the Company expects to have a material adverse effect on its financial position, results of operations or cash flows.

Equity and Stock Incentive Plan

Equity and Stock Incentive Plans	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity and Stock Incentive Plans	Equity and Stock Incentive Plans The Company recognized stock-based compensation expense related to awards granted under its 2009 Stock Option and Incentive Plan (the “2009 Plan”), 2011 Equity Incentive Award Plan (the “ 2011 Plan ”), and ESPP . Total stock-based compensation expense recognized consisted of: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (in thousands) Cost of revenues $ 1,810 $ 1,381 $ 4,929 $ 3,483 Sales and marketing 1,346 1,243 3,780 3,180 Research and development 2,043 1,969 6,002 5,417 General and administrative 3,700 4,155 10,549 11,376 $ 8,899 $ 8,748 $ 25,260 $ 23,456 2009 Stock Option and Incentive Plan and 2011 Equity Incentive Award Plan Stock Options The following table summarizes the Company’s stock option activity under the 2009 Plan and 2011 Plan : Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at January 1, 2017 1,885,332 $ 26.21 6.34 $ 108,356 Granted 6,601 94.66 Exercised (365,573 ) 23.23 Forfeited or expired (20,646 ) 40.48 Outstanding at September 30, 2017 1,505,714 $ 27.03 5.70 $ 83,042 Ending vested and expected to vest at September 30, 2017 1,498,599 $ 26.93 5.69 $ 82,809 Exercisable at September 30, 2017 1,259,159 $ 23.53 5.40 $ 73,791 There were no stock options granted during the three months ended September 30, 2017 . Stock options granted during the nine months ended September 30, 2017 were made under the 2011 Plan. There were no grants under the 2009 Plan during the nine months ended September 30, 2017 . The aggregate intrinsic value of the stock options outstanding at September 30, 2017 represents the value of the Company’s closing stock price of $82.13 on September 30, 2017 in excess of the exercise price multiplied by the number of options outstanding for options that were in-the-money. Options outstanding that are expected to vest are net of estimated future option forfeitures. As of September 30, 2017 , total unrecognized stock-based compensation expense related to unvested stock options, adjusted for estimated forfeitures, was $4.9 million and is expected to be recognized over a weighted average period of 1.3 years. Restricted Stock Units, Performance-Vesting Restricted Stock Units, and Performance Awards The following table summarizes the Company’s RSU , Performance Award, and performance-vesting RSU activity: RSUs Performance Awards and Performance-Vesting RSUs Number of Shares Weighted Average Grant Date Fair Value Per Share Number of Shares Weighted Average Grant Date Fair Value Per Share Outstanding at January 1, 2017 1,025,115 $ 64.47 407,650 $ 46.77 Granted 504,699 100.90 41,992 94.66 Released (309,089 ) 57.11 (145,651 ) 39.53 Forfeited or expired (100,817 ) 79.20 — — Outstanding at September 30, 2017 1,119,908 $ 81.59 303,991 $ 56.86 Ending vested and expected to vest at September 30, 2017 977,940 303,991 RSU s, performance-vesting RSUs, and Performance Awards that are expected to vest are presented net of estimated future forfeitures. RSU s released during the nine months ended September 30, 2017 and 2016 had an aggregate intrinsic value of $32.0 million and $16.8 million , respectively, and had an aggregate grant-date fair value of $17.7 million and $8.3 million , respectively. Performance-vesting RSUs and Performance Awards released during the nine months ended September 30, 2017 and 2016 had an aggregate intrinsic value of $13.7 million and $21.6 million , respectively, and had an aggregate grant-date fair value of $5.8 million and $6.8 million , respectively. The number of RSU s released includes shares that the Company withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements. As of September 30, 2017 , total unrecognized compensation expense related to unvested RSU s, performance-vesting RSUs, and Performance Awards was $72.3 million and is expected to be recognized over a weighted average period of 2.5 years. Employee Stock Purchase Plan For the nine months ended September 30, 2017 and 2016 , employees purchased 121,010 shares and 101,816 shares, respectively, under the ESPP for a total of $9.1 million and $6.7 million , respectively. As of September 30, 2017 , unrecognized compensation expense related to the current semi-annual ESPP offering period, which ends on February 28, 2018 , was $1.4 million and is expected to be recognized over five months. Valuation Information The fair value of stock options and stock purchase rights granted under the 2009 Plan, the 2011 Plan , and the ESPP were estimated at the date of grant using the Black-Scholes option valuation model with the following weighted average assumptions: Three months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 Stock option plans: Risk-free interest rate — % — % 2.04 % 1.38 % Expected life of options (in years) — — 6.08 6.08 Expected dividend yield — % — % — % — % Volatility — % — % 48 % 47 % Employee Stock Purchase Plan: Risk-free interest rate 1.12 % 0.46 % 0.58 % 0.36 % Expected life of options (in years) 0.49 0.50 0.49 0.50 Expected dividend yield — % — % — % — % Volatility 37 % 33 % 35 % 38 % Common Stock The following numbers of shares of common stock were reserved and available for future issuance at September 30, 2017 : Reserved Shares Options and awards outstanding under stock option plans 2,929,613 Shares available for future grant under the 2011 Plan 5,225,211 Shares available under the ESPP 1,614,689 Total 9,769,513 In February 2017 , 336,856 additional shares were reserved under the ESPP , and 1,684,282 additional shares were reserved under the 2011 Plan , pursuant to the automatic increase provisions in each plan. Stock Repurchase Program In August 2017 , the Company’s audit committee, under the authority delegated to it by the Company’s board of directors, approved a new stock repurchase program under which the Company is authorized to repurchase up to $250.0 million of its common stock. This authorization expires in August 2020 . All shares are retired upon repurchase. As of September 30, 2017, the Company had not repurchased any shares under this program.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Company operates in one industry—mortgage-related software and services. The Company’s chief operating decision maker is its chief executive officer, who makes decisions about resource allocation and reviews financial information presented on a consolidated basis. Accordingly, the Company has determined that it has a single reporting segment and operating unit structure, specifically, technology-enabled solutions to help streamline and automate the residential mortgage origination process in the United States for its network participants.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 2, 2017, the Company acquired all of the shares of Velocify, Inc. (“Velocify”), a leading cloud-based intelligent sales automation platform that provides customers the capabilities to generate and manage leads and customer relationships, in exchange for total cash consideration of approximately $130.0 million plus contingent payments of approximately $2.8 million . Given the timing of the completion of the acquisition, the Company is currently in the process of valuing the assets acquired and liabilities assumed. As a result, the Company is unable to provide the amount recognized as of the acquisition date for the major classes of assets acquired and liabilities assumed. The Company will provide these disclosures in its Annual Report on Form 10-K for the year ending December 31, 2017.

Basis of Presentation and Sig17

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management evaluates estimates on a regular basis including those relating to revenue recognition, allowance for doubtful accounts, goodwill, intangible assets, valuation of deferred income taxes, stock-based compensation, and unrecognized tax benefits, among others. Actual results could differ from those estimates, and such differences may have a material impact on the Company’s condensed consolidated financial statements and footnotes.
Significant Accounting Policies	Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements in its 2016 Form 10-K . There have been no significant changes to these policies during the nine months ended September 30, 2017 , except in relation to the Company’s adoption of ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Shared-Based Payment Accounting (“ASU 2016-09”) on January 1, 2017, whereby the Company now records excess tax benefits and tax deficiencies as an income tax benefit or expense when stock awards vest or settle, and the Company no longer classifies the cash flow from excess tax benefits as a reduction from operating cash flows.
Comprehensive Income	Comprehensive Income Comprehensive income consists of net income and other comprehensive income . Other comprehensive income includes certain changes in equity that are excluded from net income, specifically unrealized gains on marketable securities.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“ FASB ”) issued Accounting Standards Update (“ ASU ”) No. 2014-09, Revenue from Contracts with Customers (“ ASU 2014-09 ”), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This standard also requires significantly expanded disclosures about revenue recognition. The effective date for public entities is fiscal years beginning after December 15, 2017 and early adoption is allowed. The Company will adopt the new standard as of January 1, 2018. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (modified retrospective method). The Company currently anticipates adopting the standard using the modified retrospective method and is continuing to evaluate the impact of the new standard on its accounting policies, processes, and systems, including impacts from guidance issued by the FASB Transition Resource Group. The Company has assigned internal resources, engaged a third-party service provider, and is in the process of updating its systems and continuing the evaluation of the quantitative impact to our financial statements. The Company expects an impact to its Encompass subscription and professional services revenue streams due to the removal of the current limitation on contingent revenue, which may affect the timing and allocation of revenues being recognized for certain contracts. The Company has also identified potential impacts to the costs to obtain contracts, which is primarily comprised of sales commissions and the related fringe benefits associated with non-cancelable contracts. The Company expects to capitalize certain costs that are expensed under the current standard, and the Company expects an increase in the amortization period over which the capitalized costs will be recognized and is continuing to evaluate the impact to the expected period of benefit under ASU 2014-09. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company is currently evaluating the impact of this accounting standard update on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to put most leases on their balance sheets but recognize the expenses on their income statements in a manner similar to current practice. ASU 2016-02 states that a lessee would recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. The standard is effective for interim and annual periods beginning after December 15, 2018, and early adoption is permitted. The Company currently does not intend to early adopt and is evaluating the impact of this accounting standard update on its consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), which provides guidance on determining which changes to the terms and conditions of share-based payment awards require an entity to apply modification accounting under Topic 718. ASU 2017-09 is effective for interim and annual periods beginning after December 15, 2017, and early adoption is permitted. The Company is currently evaluating the timing of adoption and does not expect the adoption of the accounting standard update to have a material impact on its consolidated financial statements.

Net Income Per Share of Commo18

Net Income Per Share of Common Stock (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Components of net income per share of common stock	The components of net income per share of common stock were as follows: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (in thousands, except share and per share amounts) Net income $ 14,519 $ 13,780 $ 42,941 $ 26,874 Basic shares: Weighted average common shares outstanding 34,275,116 31,916,910 34,004,025 30,407,020 Diluted shares: Weighted average shares used to compute basic net income per share 34,275,116 31,916,910 34,004,025 30,407,020 Effect of potentially dilutive securities: Employee stock options, RSUs, performance-vesting RSUs, Performance Awards and ESPP shares 1,509,856 1,565,623 1,799,792 1,632,063 Weighted average shares used to compute diluted net income per share 35,784,972 33,482,533 35,803,817 32,039,083 Net income per share: Basic $ 0.42 $ 0.43 $ 1.26 $ 0.88 Diluted $ 0.41 $ 0.41 $ 1.20 $ 0.84
Common shares excluded from computation of diluted net income per share	The following potential weighted average common shares were excluded from the computation of diluted net income per share, as their effect would have been anti-dilutive: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 Employee stock options and awards 319,922 — 179,091 42,036

Financial Instruments and Fai19

Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Financial Instruments and Fair Value Measurements [Abstract]
Fair value hierarchy of financial assets on recurring basis	The following tables set forth by level within the fair value hierarchy the Company’s financial assets that were accounted for at fair value on a recurring basis: September 30, 2017 December 31, 2016 Level 1 Level 2 Total Level 1 Level 2 Total (in thousands) (in thousands) Cash equivalents: Money market funds $ 4,363 $ — $ 4,363 $ 2,733 $ — $ 2,733 Corporate notes and obligations — 17,327 17,327 — — — U.S. government and government agency obligations 6,575 14,829 21,404 151,660 149,976 301,636 Investments: Certificates of deposit — 8,140 8,140 — 12,088 12,088 Corporate notes and obligations — 73,713 73,713 — 28,892 28,892 Municipal obligations — 10,475 10,475 — 11,361 11,361 U.S. government and government agency obligations 51,021 88,852 139,873 4,579 30,852 35,431 $ 61,959 $ 213,336 $ 275,295 $ 158,972 $ 233,169 $ 392,141
Carrying amounts, gross unrealized gains and losses, and estimated fair value of cash and investments	The carrying amounts, gross unrealized gains and losses and estimated fair value of cash and cash equivalents and both short-term and long-term investments consisted of the following: September 30, 2017 December 31, 2016 Amortized Cost Unrealized Gains Unrealized Losses Carrying or Fair Value Amortized Unrealized Gains Unrealized Losses Carrying or (in thousands) (in thousands) Cash and cash equivalents: Cash $ 203,738 $ — $ — $ 203,738 $ 76,538 $ — $ — $ 76,538 Money market funds 4,363 — — 4,363 2,733 — — 2,733 Corporate notes and obligations 17,327 — — 17,327 — — — — U.S. government and government agency obligations 21,403 1 — 21,404 301,631 8 (3 ) 301,636 $ 246,831 $ 1 $ — $ 246,832 $ 380,902 $ 8 $ (3 ) $ 380,907 Investments: Corporate notes and obligations $ 73,754 $ 26 $ (67 ) $ 73,713 $ 28,978 $ 1 $ (87 ) $ 28,892 Certificates of deposit 8,138 3 (1 ) 8,140 12,094 13 (19 ) 12,088 Municipal obligations 10,471 11 (7 ) 10,475 11,422 1 (62 ) 11,361 U.S. government and government agency obligations 140,050 2 (179 ) 139,873 35,502 8 (79 ) 35,431 $ 232,413 $ 42 $ (254 ) $ 232,201 $ 87,996 $ 23 $ (247 ) $ 87,772
Schedule of investments in continuous unrealized loss position	The following table shows the gross unrealized losses and the related fair values of the Company’s investments that have been in a continuous unrealized loss position. The Company did not identify any investments as other-than-temporarily impaired at September 30, 2017 or December 31, 2016 based on its evaluation of available evidence, such as the Company’s intent to hold and whether it is more likely than not that the Company will be required to sell the investment before recovery of the investment’s amortized basis. The Company expects to receive the full principal and interest on these investments. September 30, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Corporate notes and obligations $ 31,732 $ (32 ) $ 7,710 $ (35 ) $ 39,442 $ (67 ) Certificates of deposit 2,452 — 245 (1 ) 2,697 (1 ) U.S. government, government agency, and municipal obligations 124,336 (154 ) 5,500 (32 ) 129,836 (186 ) $ 158,520 $ (186 ) $ 13,455 $ (68 ) $ 171,975 $ (254 ) December 31, 2016 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Corporate notes and obligations $ 26,076 $ (87 ) $ — $ — $ 26,076 $ (87 ) Certificates of deposit 5,651 (19 ) — — 5,651 (19 ) U.S. government, government agency, and municipal obligations 180,138 (144 ) 385 — 180,523 (144 ) $ 211,865 $ (250 ) $ 385 $ — $ 212,250 $ (250 )
Summary of the maturities of investments	The following table summarizes the maturities of the Company’s investments at September 30, 2017 : Carrying or Fair Value (in thousands) Remainder of 2017 $ 28,276 2018 102,878 2019 72,308 2020 28,739 Total $ 232,201

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2017
Statement of Financial Position [Abstract]
Schedule of property and equipment	Property and equipment, net, consisted of the following: September 30, December 31, 2017 2016 (in thousands) Computer equipment and software (1) (2) $ 66,871 $ 54,029 Internal-use software (2) 96,022 62,573 Furniture and fixtures 9,218 6,838 Leasehold improvements 29,389 18,532 Property and equipment 201,500 141,972 Accumulated depreciation and amortization (1) (75,015 ) (48,991 ) Subtotal 126,485 92,981 Internal-use software and other assets not placed in service 40,379 33,316 Property and equipment, net $ 166,864 $ 126,297 ________________ (1) Includes computer equipment and software under capital leases (2) Certain reclassifications of prior period amounts have been made to conform to the current period presentation, such reclassification did not materially change previously reported consolidated financial statements. Computer equipment and software under capital leases, net, consisted of the following: September 30, December 31, 2017 2016 (in thousands) Computer equipment $ 8,715 $ 8,715 Software 1,517 1,517 Accumulated depreciation and amortization (8,676 ) (6,522 ) Net computer equipment and software under capital leases $ 1,556 $ 3,710
Schedule accrued and other current liabilities	Accrued and other current liabilities consisted of the following: September 30, December 31, 2017 2016 (in thousands) Accrued payroll and related expenses $ 15,281 $ 31,848 Accrued commissions 643 1,832 Accrued royalties 1,828 1,395 Sales and other taxes 1,298 2,327 Other accrued liabilities (1) 2,071 2,407 $ 21,121 $ 39,809 ________________ (1) Certain reclassifications of prior period amounts have been made to conform to the current period presentation, such reclassification did not materially change previously reported consolidated financial statements.

Goodwill and Intangible Asset21

Goodwill and Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets, net	Intangible assets, net, consisted of the following: September 30, 2017 Gross Carrying Accumulated Net Intangibles Weighted Average Remaining Useful Life (in thousands) (in years) Assets subject to amortization: Developed technology $ 11,535 $ (9,181 ) $ 2,354 2.1 Trade names 331 (331 ) — 0.0 Customer relationships 19,400 (11,928 ) 7,472 3.4 Order backlog 370 (179 ) 191 2.1 Total assets subject to amortization: 31,636 (21,619 ) 10,017 3.1 Assets not subject to amortization: Trade name 4,039 — 4,039 $ 35,675 $ (21,619 ) $ 14,056 December 31, 2016 Gross Carrying Accumulated Net Intangibles Weighted Average Remaining Useful Life (in thousands) (in years) Assets subject to amortization: Developed technology $ 11,535 $ (8,183 ) $ 3,352 2.7 Trade names 331 (331 ) — 0.0 Customer relationships 19,400 (9,762 ) 9,638 4.0 Order backlog 370 (110 ) 260 2.8 Total assets subject to amortization: 31,636 (18,386 ) 13,250 3.6 Assets not subject to amortization: Trade name 4,039 — 4,039 $ 35,675 $ (18,386 ) $ 17,289
Minimum future amortization expense for intangible assets	Future amortization expense for intangible assets at September 30, 2017 was as follows: Amortization (in thousands) Remainder of 2017 $ 1,061 2018 3,443 2019 3,166 2020 1,778 2021 314 2022 255 $ 10,017

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax provision	The estimated annual effective tax rate as of September 30, 2017 and 2016 was 35.9% and 36.5% , respectively. Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (dollars in thousands) (dollars in thousands) Income tax provision (benefit) $ 4,465 $ 7,492 $ (964 ) $ 14,966 Effective tax rate (1) 23.5 % 35.2 % (2.3 )% 35.8 % ________________ (1) The impact to the effective tax rate due to the excess tax benefits of stock-based compensation from the adoption of ASU 2016-09 was 12.0% and 37.0% for the three and nine months ended September 30, 2017 , respectively.

Equity and Stock Incentive Pl23

Equity and Stock Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	Total stock-based compensation expense recognized consisted of: Three Months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 (in thousands) Cost of revenues $ 1,810 $ 1,381 $ 4,929 $ 3,483 Sales and marketing 1,346 1,243 3,780 3,180 Research and development 2,043 1,969 6,002 5,417 General and administrative 3,700 4,155 10,549 11,376 $ 8,899 $ 8,748 $ 25,260 $ 23,456
Summary of stock option activity	The following table summarizes the Company’s stock option activity under the 2009 Plan and 2011 Plan : Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at January 1, 2017 1,885,332 $ 26.21 6.34 $ 108,356 Granted 6,601 94.66 Exercised (365,573 ) 23.23 Forfeited or expired (20,646 ) 40.48 Outstanding at September 30, 2017 1,505,714 $ 27.03 5.70 $ 83,042 Ending vested and expected to vest at September 30, 2017 1,498,599 $ 26.93 5.69 $ 82,809 Exercisable at September 30, 2017 1,259,159 $ 23.53 5.40 $ 73,791
Summary of RSU, Performance Award, and performance-vesting RSU activity	The following table summarizes the Company’s RSU , Performance Award, and performance-vesting RSU activity: RSUs Performance Awards and Performance-Vesting RSUs Number of Shares Weighted Average Grant Date Fair Value Per Share Number of Shares Weighted Average Grant Date Fair Value Per Share Outstanding at January 1, 2017 1,025,115 $ 64.47 407,650 $ 46.77 Granted 504,699 100.90 41,992 94.66 Released (309,089 ) 57.11 (145,651 ) 39.53 Forfeited or expired (100,817 ) 79.20 — — Outstanding at September 30, 2017 1,119,908 $ 81.59 303,991 $ 56.86 Ending vested and expected to vest at September 30, 2017 977,940 303,991
Schedule of stock options and employee stock purchase plan valuation assumptions	The fair value of stock options and stock purchase rights granted under the 2009 Plan, the 2011 Plan , and the ESPP were estimated at the date of grant using the Black-Scholes option valuation model with the following weighted average assumptions: Three months ended September 30, Nine Months ended September 30, 2017 2016 2017 2016 Stock option plans: Risk-free interest rate — % — % 2.04 % 1.38 % Expected life of options (in years) — — 6.08 6.08 Expected dividend yield — % — % — % — % Volatility — % — % 48 % 47 % Employee Stock Purchase Plan: Risk-free interest rate 1.12 % 0.46 % 0.58 % 0.36 % Expected life of options (in years) 0.49 0.50 0.49 0.50 Expected dividend yield — % — % — % — % Volatility 37 % 33 % 35 % 38 %
Schedule of shares of common stock available for future issuance under stock option plans	The following numbers of shares of common stock were reserved and available for future issuance at September 30, 2017 : Reserved Shares Options and awards outstanding under stock option plans 2,929,613 Shares available for future grant under the 2011 Plan 5,225,211 Shares available under the ESPP 1,614,689 Total 9,769,513

Basis of Presentation and Sig24

Basis of Presentation and Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities	$ 69,621	$ 61,108
Net cash provided by (used in) financing activities	$ 4,743	279,034
ASU No. 2016-09 [Member] | Reclassification [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		5,500
Net cash provided by (used in) financing activities		$ (5,500)

Net Income Per Share of Commo25

Net Income Per Share of Common Stock (Components of Computation) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Components of net income per share
Net income	$ 14,519	$ 13,780	$ 42,941	$ 26,874
Basic shares:
Weighted average common shares outstanding	34,275,116	31,916,910	34,004,025	30,407,020
Diluted shares:
Weighted average common shares outstanding	34,275,116	31,916,910	34,004,025	30,407,020
Effect of potentially dilutive securities:
Employee stock options, RSUs, performance-vesting RSUs, Performance Awards and ESPP shares	1,509,856	1,565,623	1,799,792	1,632,063
Weighted average shares used to compute diluted net income per share	35,784,972	33,482,533	35,803,817	32,039,083
Net income per share:
Basic (in usd per share)	$ 0.42	$ 0.43	$ 1.26	$ 0.88
Diluted (in usd per share)	$ 0.41	$ 0.41	$ 1.20	$ 0.84

Net Income Per Share of Commo26

Net Income Per Share of Common Stock (Anti-dilutive Shares Excluded From Computation) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Employee Stock Options and Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net income per share	319,922	0	179,091	42,036
Performance Based Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net income per share	59,455	167,336	59,455	167,336

Financial Instruments and Fai27

Financial Instruments and Fair Value Measurements (Fair Value Hierarchy) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	$ 275,295	$ 392,141
Money market funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	4,363	2,733
Certificates of deposit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	8,140	12,088
Corporate notes and obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	17,327	0
Investments	73,713	28,892
Municipal obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	10,475	11,361
U.S. government and government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	21,404	301,636
Investments	139,873	35,431
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	61,959	158,972
Level 1 [Member] | Money market funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	4,363	2,733
Level 1 [Member] | Certificates of deposit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Level 1 [Member] | Corporate notes and obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Investments	0	0
Level 1 [Member] | Municipal obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Level 1 [Member] | U.S. government and government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	6,575	151,660
Investments	51,021	4,579
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	213,336	233,169
Level 2 [Member] | Money market funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Level 2 [Member] | Certificates of deposit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	8,140	12,088
Level 2 [Member] | Corporate notes and obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	17,327	0
Investments	73,713	28,892
Level 2 [Member] | Municipal obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	10,475	11,361
Level 2 [Member] | U.S. government and government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	14,829	149,976
Investments	$ 88,852	$ 30,852

Financial Instruments and Fai28

Financial Instruments and Fair Value Measurements (Carrying Amounts and Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Cash and cash equivalents:
Cash and cash equivalents, carrying value	$ 246,832	$ 380,907	$ 344,539	$ 34,396
Investments:
Investments, amortized cost	232,413	87,996
Unrealized Gains	42	23
Unrealized Losses	(254)	(247)
Investments	232,201	87,772
Corporate notes and obligations [Member]
Investments:
Investments, amortized cost	73,754	28,978
Unrealized Gains	26	1
Unrealized Losses	(67)	(87)
Investments	73,713	28,892
Certificates of deposit [Member]
Investments:
Investments, amortized cost	8,138	12,094
Unrealized Gains	3	13
Unrealized Losses	(1)	(19)
Investments	8,140	12,088
Municipal obligations [Member]
Investments:
Investments, amortized cost	10,471	11,422
Unrealized Gains	11	1
Unrealized Losses	(7)	(62)
Investments	10,475	11,361
U.S. government and government agency obligations [Member]
Investments:
Investments, amortized cost	140,050	35,502
Unrealized Gains	2	8
Unrealized Losses	(179)	(79)
Investments	139,873	35,431
Cash [Member]
Cash and cash equivalents:
Cash	203,738	76,538
Cash Equivalents [Member]
Cash and cash equivalents:
Money market funds	4,363	2,733
Cash and cash equivalents, amortized cost	246,831	380,902
Cash and cash equivalents, carrying value	246,832	380,907
Investments:
Unrealized Gains	1	8
Unrealized Losses	0	(3)
Cash Equivalents [Member] | Corporate notes and obligations [Member]
Cash and cash equivalents:
Cash and cash equivalents, amortized cost	17,327
Cash equivalents, carrying value	17,327
Cash Equivalents [Member] | U.S. government and government agency obligations [Member]
Cash and cash equivalents:
Cash and cash equivalents, amortized cost	21,403	301,631
Cash equivalents, carrying value	21,404	301,636
Investments:
Unrealized Gains	1	8
Unrealized Losses	$ 0	$ (3)

Financial Instruments and Fai29

Financial Instruments and Fair Value Measurements (Continuous Unrealized Loss) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 158,520	$ 211,865
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(186)	(250)
12 Months or Greater, Fair Value	13,455	385
Continuous Unrealized Loss Position, 12 Months or Greater, Accumulated Loss	(68)	0
Fair Value	171,975	212,250
Continuous Unrealized Loss Position, Accumulated Loss	(254)	(250)
Corporate notes and obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	31,732	26,076
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(32)	(87)
12 Months or Greater, Fair Value	7,710	0
Continuous Unrealized Loss Position, 12 Months or Greater, Accumulated Loss	(35)	0
Fair Value	39,442	26,076
Continuous Unrealized Loss Position, Accumulated Loss	(67)	(87)
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	2,452	5,651
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(19)
12 Months or Greater, Fair Value	245	0
Continuous Unrealized Loss Position, 12 Months or Greater, Accumulated Loss	(1)	0
Fair Value	2,697	5,651
Continuous Unrealized Loss Position, Accumulated Loss	(1)	(19)
U.S. government and government agency obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	124,336	180,138
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(154)	(144)
12 Months or Greater, Fair Value	5,500	385
Continuous Unrealized Loss Position, 12 Months or Greater, Accumulated Loss	(32)	0
Fair Value	129,836	180,523
Continuous Unrealized Loss Position, Accumulated Loss	$ (186)	$ (144)

Financial Instruments and Fai30

Financial Instruments and Fair Value Measurements (Summary of Investment Maturities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Maturities of the Company's Investments
Investments, Maturities, Remainder of Fiscal Year, Fair Value	$ 28,276
Investments, Maturities, Next Fiscal Year, Fair Value	102,878
Investments, Maturities, In Two Years, Fair Value	72,308
Investments, Maturities, In Three Years, Fair Value	28,739
Total	$ 232,201	$ 87,772

Financial Instruments and Fai31

Financial Instruments and Fair Value Measurements (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Financial Instruments and Fair Value Measurements [Abstract]
Transfers of financial instruments between fair value levels	$ 0	$ 0

Balance Sheet Components (Prope

Balance Sheet Components (Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property and Equipment, Net
Property and equipment, gross	$ 201,500	$ 141,972
Accumulated depreciation and amortization	(75,015)	(48,991)
Property and equipment, gross subtotal	126,485	92,981
Internal-use software and other assets not placed in service	40,379	33,316
Property and equipment, net	166,864	126,297
Computer Equipment and Software Under Capital Leases
Accumulated depreciation and amortization, capital lease	(8,676)	(6,522)
Net computer equipment and software under capital leases	1,556	3,710
Computer Equipment and Software [Member]
Property and Equipment, Net
Property and equipment, gross	66,871	54,029
Internal-Use Software [Member]
Property and Equipment, Net
Property and equipment, gross	96,022	62,573
Furniture and Fixtures [Member]
Property and Equipment, Net
Property and equipment, gross	9,218	6,838
Leasehold Improvements [Member]
Property and Equipment, Net
Property and equipment, gross	29,389	18,532
Computer Equipment [Member]
Computer Equipment and Software Under Capital Leases
Capital leased assets, gross	8,715	8,715
Software [Member]
Computer Equipment and Software Under Capital Leases
Capital leased assets, gross	$ 1,517	$ 1,517

Balance Sheet Components (Detai

Balance Sheet Components (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Financial Position [Abstract]
Depreciation and amortization expense	$ 9,700	$ 5,800	$ 26,024	$ 14,487
Depreciation and amortization expense, capital lease	$ 600	$ 800	$ 2,200	$ 2,400

Balance Sheet Components (Accru

Balance Sheet Components (Accrued and Other Current Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accrued and Other Current Liabilities [Line Items]
Accrued payroll and related expenses	$ 15,281	$ 31,848
Accrued commissions	643	1,832
Accrued royalties	1,828	1,395
Sales and other taxes	1,298	2,327
Other accrued liabilities	2,071	2,407
Accrued and other current liabilities	$ 21,121	$ 39,809

Goodwill and Intangible Asset35

Goodwill and Intangible Assets, Net (Schedule of Goodwill) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 74,547,000	$ 74,547,000	$ 74,547,000
Goodwill, change in carrying value	$ 0	$ 0

Goodwill and Intangible Asset36

Goodwill and Intangible Assets, Net (Intangible Assets Gross and Net Balances) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, gross	$ 35,675	$ 35,675
Intangible Assets, net	14,056	17,289
Assets subject to amortization:
Gross Carrying Amount	31,636	31,636
Accumulated Amortization	(21,619)	(18,386)
Net Intangibles, finite-lived	$ 10,017	$ 13,250
Weighted Average Remaining Useful Life (in years)	36 months 21 days	43 months 17 days
Trade Names [Member]
Assets not subject to amortization:
Net Intangibles, indefinite-lived	$ 4,039	$ 4,039
Developed Technology [Member]
Assets subject to amortization:
Gross Carrying Amount	11,535	11,535
Accumulated Amortization	(9,181)	(8,183)
Net Intangibles, finite-lived	$ 2,354	$ 3,352
Weighted Average Remaining Useful Life (in years)	24 months 20 days	32 months 21 days
Trade Names [Member]
Assets subject to amortization:
Gross Carrying Amount	$ 331	$ 331
Accumulated Amortization	(331)	(331)
Net Intangibles, finite-lived	$ 0	$ 0
Weighted Average Remaining Useful Life (in years)	1 day	1 day
Customer Relationships [Member]
Assets subject to amortization:
Gross Carrying Amount	$ 19,400	$ 19,400
Accumulated Amortization	(11,928)	(9,762)
Net Intangibles, finite-lived	$ 7,472	$ 9,638
Weighted Average Remaining Useful Life (in years)	40 months 23 days	47 months 18 days
Order Backlog [Member]
Assets subject to amortization:
Gross Carrying Amount	$ 370	$ 370
Accumulated Amortization	(179)	(110)
Net Intangibles, finite-lived	$ 191	$ 260
Weighted Average Remaining Useful Life (in years)	25 months	34 months

Goodwill and Intangible Asset37

Goodwill and Intangible Assets, Net (Intangible Assets Future Amortization) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Minimum future amortization expense for intangible assets
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 1,061
Finite-Lived Intangible Assets, Amortization Expense, Next Fiscal Year	3,443
Finite-Lived Intangible Assets, Amortization Expense, in Two Years	3,166
Finite-Lived Intangible Assets, Amortization Expense, in Three Years	1,778
Finite-Lived Intangible Assets, Amortization Expense, in Four Years	314
Finite-Lived Intangible Assets, Amortization Expense, in Five Years	255
Finite-Lived Intangible Assets, Net	$ 10,017	$ 13,250

Goodwill and Intangible Asset38

Goodwill and Intangible Assets, Net (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 1,100	$ 1,500	$ 3,233	$ 4,442

Income Taxes (Tax Provision and

Income Taxes (Tax Provision and Effective Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income tax provision (benefit)	$ 4,465	$ 7,492	$ (964)	$ 14,966
Effective tax rate (percent)	23.50%	35.20%	(2.30%)	35.80%

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Estimated annual effective tax rate (percent)			35.90%	36.50%
Favorable impact on effective tax rate due to adoption of new accounting standard (percent)	12.00%		37.00%
Effective tax rate (percent)	23.50%	35.20%	(2.30%)	35.80%
Federal statutory tax rate (percent)	35.00%		35.00%
Excess tax benefit from share-based compensation	$ 2,300		$ 15,500
Income tax interest and penalties			$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details Textual)	Sep. 30, 2017facility
Commitments and Contingencies Disclosure [Abstract]
Number of facilities under operating lease arrangements	8

Equity and Stock Incentive Pl42

Equity and Stock Incentive Plans (Stock-Based Compensation Allocation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 8,899	$ 8,748	$ 25,260	$ 23,456
Cost of Revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,810	1,381	4,929	3,483
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,346	1,243	3,780	3,180
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,043	1,969	6,002	5,417
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,700	$ 4,155	$ 10,549	$ 11,376

Equity and Stock Incentive Pl43

Equity and Stock Incentive Plans (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options granted, shares	0
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning of period, shares		1,885,332
Options granted, shares		6,601
Options exercised, shares		(365,573)
Options forfeited or expired, shares		(20,646)
Options outstanding, end of period, shares	1,505,714	1,505,714	1,885,332
Ending vested and expected to vest, end of period, shares	1,498,599	1,498,599
Options exercisable, end of period, shares	1,259,159	1,259,159
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of period, weighted average exercise price		$ 26.21
Options granted, weighted average exercise price		94.66
Options exercised, weighted average exercise price		23.23
Options forfeited or expired, weighted average exercise price		40.48
Outstanding, end of period, weighted average exercise price	$ 27.03	27.03	$ 26.21
Ending vested and expected to vest, Weighted Average Exercise Price at End of Period	26.93	26.93
Stock option exercisable at End of Period, weighted average exercise price, Ending Balance	$ 23.53	$ 23.53
Weighted average remaining contractual term at End of Period		5 years 256 days	6 years 124 days
Ending vested and expected to vest, Weighted Average Remaining Contractual Term at End of Period		5 years 252 days
Stock option exercisable, weighted average remaining Contractual term, Ending balance		5 years 146 days
Aggregate Intrinsic value at End of Period	$ 83,042	$ 83,042	$ 108,356
Ending vested and expected to vest, Aggregate Intrinsic Value at End of Period	82,809	82,809
Exercisable aggregate Intrinsic Value	$ 73,791	$ 73,791

Equity and Stock Incentive Pl44

Equity and Stock Incentive Plans (RSU and Performance Award Activity) (Details)	9 Months Ended
	Sep. 30, 2017$ / sharesshares
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding, beginning of period	1,025,115
Granted	504,699
Released	(309,089)
Forfeited or expired	(100,817)
Outstanding, end of period	1,119,908
Weighted Average Grant Date Fair Value, beginning of period | $ / shares	$ 64.47
Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	100.90
Released in Period, Weighted Average Grant Date Fair Value | $ / shares	57.11
Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	79.20
Weighted Average Grant Date Fair Value, end of period | $ / shares	$ 81.59
Ending vested and expected to vest, end of period, shares	977,940
Performance Awards and Performance-Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding, beginning of period	407,650
Granted	41,992
Released	(145,651)
Forfeited or expired	0
Outstanding, end of period	303,991
Weighted Average Grant Date Fair Value, beginning of period | $ / shares	$ 46.77
Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	94.66
Released in Period, Weighted Average Grant Date Fair Value | $ / shares	39.53
Forfeitures, Weighted Average Grant Date Fair Value | $ / shares	0
Weighted Average Grant Date Fair Value, end of period | $ / shares	$ 56.86
Ending vested and expected to vest, end of period, shares	303,991

Equity and Stock Incentive Pl45

Equity and Stock Incentive Plans (Fair Value Assumptions) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock Option [Member]
Schedule of Stock Options and Employee Stock Purchase Plan Valuation Assumptions
Risk-free interest rate	0.00%	0.00%	2.04%	1.38%
Expected life of options (in years)			6 years 29 days	6 years 29 days
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Volatility	0.00%	0.00%	48.00%	47.00%
Employee Stock Purchase Plan [Member]
Schedule of Stock Options and Employee Stock Purchase Plan Valuation Assumptions
Risk-free interest rate	1.12%	0.46%	0.58%	0.36%
Expected life of options (in years)	179 days	6 months	179 days	6 months
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Volatility	37.00%	33.00%	35.00%	38.00%

Equity and Stock Incentive Pl46

Equity and Stock Incentive Plans (Reserved Shares) (Details)	Sep. 30, 2017shares
Class of Stock [Line Items]
Reserved shares	9,769,513
Options and Awards Outstanding [Member]
Class of Stock [Line Items]
Reserved shares	2,929,613
Shares Available for Future Grant [Member]
Class of Stock [Line Items]
Reserved shares	5,225,211
Shares Available Under Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Reserved shares	1,614,689

Equity and Stock Incentive Pl47

Equity and Stock Incentive Plans (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Aug. 31, 2017	Feb. 28, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, shares	0
Stock repurchase program, authorized amount				$ 250,000,000
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, shares		6,601
Share price (in usd per share)	$ 82.13	$ 82.13
Unrecognized stock-based compensation expense	$ 4,900,000	$ 4,900,000
Expected to be recognized over a weighted average period		1 year 92 days
Annual automatic increase in shares reserved for issuance, shares					1,684,282
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of shares released		$ 32,000,000	$ 16,800,000
Aggregate grant-date fair value of shares released		17,700,000	8,300,000
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of shares released		13,700,000	21,600,000
Aggregate grant-date fair value of shares released		5,800,000	$ 6,800,000
Restricted Stock Units and Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	72,300,000	$ 72,300,000
Expected to be recognized over a weighted average period		2 years 186 days
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual automatic increase in shares reserved for issuance, shares					336,856
2009 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, shares		0
Employee Stock Purchase Plan [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares purchased under ESPP		121,010	101,816
Purchase price of ESPP shares		$ 9,100,000	$ 6,700,000
Unrecognized compensation cost related to employee stock purchase plan	$ 1,400,000	$ 1,400,000
Expected recognized period under employee stock purchase plan		5 months

Subsequent Events (Details Text

Subsequent Events (Details Textual) - Subsequent Event [Member] - Velocify Inc [Member] $ in Millions	Oct. 02, 2017USD ($)
Subsequent Event [Line Items]
Cash consideration	$ 130
Contingent payments for acquisition	$ 2.8