Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income (loss)		$ 14,898	$ 13,710	[1]
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization		29,363	23,889	[1]
Stock-based compensation expense		50,236	49,346	[1]
(Gain) loss from foreign currency, sales of investments, assets and other, net		497	(206)	[1]
(Accretion) and amortization on marketable debt securities, net		(2,043)	(172)	[1]
Noncash consideration received		(1,494)
Change in deferred income taxes and other		(1,809)	4,222	[1]
Changes in operating assets and liabilities:
Accounts receivable, net		7,302	(12,150)	[1]
Other assets		(14,833)	359	[1]
Accounts payable		(18,613)	(6,012)	[1]
Deferred revenue		43,758	1,913	[1]
Income tax payable		(5,180)	2,003	[1]
Other liabilities		(23,770)	(8,907)	[1]
Net cash provided by (used in) operating activities		78,312	67,995	[1]
Cash flows from investing activities:
Purchases of short-term investments		(267,435)	(255,301)	[1]
Maturities of short-term investments		384,300
Sales of short-term investments		9,999
Acquisition of property and equipment		(7,505)	(6,878)	[1]
Proceeds from sale of property and equipment		33	221	[1]
Business acquisitions, net of cash acquired and restricted cash held in escrow		(222,075)	(27,581)	[1]
Release of restricted cash escrow from business combinations		(22,800)	(2,500)	[1]
Other investing activities, net		375	(7,225)	[1]
Net cash provided by (used in) investing activities		(125,108)	(299,264)	[1]
Cash flows from financing activities:
Taxes paid related to net share settlement of stockholders' equity awards		(19,363)	(14,576)	[1]
Repurchases of common stock		(73,811)	(96,924)	[1]
Proceeds from issuance of common stock		8,925	8,249	[1]
Acquisition-related contingent consideration payment	[1]		(5,115)
Net cash provided by (used in) financing activities		(84,249)	(108,366)	[1]
Effect of exchange rate changes on cash, cash equivalents and restricted cash		(3,179)	4,108	[1]
Net change in cash, cash equivalents and restricted cash		(134,224)	(335,527)	[1]
Cash, cash equivalents and restricted cash, beginning of period		405,677	861,716	[1]
Cash, cash equivalents and restricted cash, end of period		271,453	526,189	[1]
Supplemental cash flow information:
Income taxes paid		13,991	$ 3,559	[1]
Noncash investing activity:
Software acquired as noncash consideration		$ 1,494

[1] Prior period amounts retrospectively adjusted to reflect the adoption of ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash”. Refer to Note 1 – “Overview and Summary of Significant Accounting Policies” in the notes to the interim consolidated financial statements for further discussion on the adoption.