Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (128,828)	$ 5,609
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	21,080	7,731
Stock-based compensation expense	18,773	14,113
(Gain) loss from foreign currency, sales of investments, assets and other, net	154	1,951
(Accretion) and amortization on marketable debt securities, net	(153)	(549)
Noncash lease expense	1,449
Change in deferred income taxes and other	(20,374)	1,322
Changes in operating assets and liabilities:
Accounts receivable, net	(30,001)	10,682
Prepaid expenses and other assets	3,318	(4,786)
Accounts payable	(14,293)	(9,574)
Deferred revenue	86,474	11,234
Income tax payable	(5,361)	(5,004)
Operating lease and other liabilities	69,309	(36,676)
Net cash provided by (used in) operating activities	1,547	(3,947)
Cash flows from investing activities:
Purchases of investments	(29,756)	(124,822)
Maturities of investments	8,500	160,000
Sales of investments	4,987
Acquisition of property and equipment	(5,058)	(1,424)
Proceeds from sale of property and equipment	46	25
Business acquisitions, net of cash acquired and restricted cash held in escrow	(299,357)
Release of restricted cash escrow from business combinations		(22,800)
Net cash provided by (used in) investing activities	(320,638)	10,979
Cash flows from financing activities:
Taxes paid related to net share settlement of stockholders' equity awards	(11,010)	(6,364)
Repurchases of common stock		(39,544)
Proceeds from issuance of common stock	4,939	3,311
Repayment of debt	(1,364)
Other financing activities, net	(326)
Net cash provided by (used in) financing activities	(7,761)	(42,597)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	11,605	1,476
Net change in cash, cash equivalents and restricted cash	(315,247)	(34,089)
Cash, cash equivalents and restricted cash, beginning of period	579,996	405,677
Cash, cash equivalents and restricted cash, end of period	264,749	371,588
Noncash investing activity:
Acquisition-related common stock issuance	253,903
Noncash financing activities:
Unsettled stock option exercise	$ 365
Unsettled repurchases of common stock		$ 1,631