Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 626,698	$ (26,704)	$ (116,846)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	252,114	149,604	113,875
Amortization of deferred commissions	168,014	143,358	99,105
Amortization of debt discount and issuance costs	33,283	52,733	53,394
Stock-based compensation	662,195	543,953	394,004
Deferred income taxes	(575,765)	(34,180)	(5,724)
Realized gain on marketable equity securities	0	(19,257)	0
Repayments of convertible senior notes attributable to debt discount	0	(145,349)	0
Other	(8,921)	6,177	(905)
Changes in operating assets and liabilities, net of effect of business combinations:
Accounts receivable	(259,835)	(146,148)	(99,693)
Deferred commissions	(255,605)	(239,382)	(190,246)
Prepaid expenses and other assets	(29,907)	(19,886)	(34,288)
Accounts payable	21,355	(4,757)	(5,504)
Deferred revenue	537,249	468,856	369,242
Accrued expenses and other liabilities	65,097	82,071	66,526
Net cash provided by operating activities	1,235,972	811,089	642,940
Cash flows from investing activities:
Purchases of property and equipment	(264,892)	(224,462)	(150,510)
Business combinations, net of cash and restricted cash acquired	(7,414)	(37,440)	(58,203)
Purchases of other intangibles	(72,689)	(24,400)	(6,670)
Purchases of investments	(1,595,667)	(1,295,782)	(1,194,261)
Sales of investments	33,503	39,975	85,106
Maturities of investments	1,159,247	1,194,687	440,590
Realized gains on derivatives not designated as hedging instruments, net	23,435	0	0
Net cash used in investing activities	(724,477)	(347,422)	(883,948)
Cash flows from financing activities:
Net proceeds from borrowings on convertible senior notes	0	0	772,127
Repayments of convertible senior notes attributable to principal	(9)	(429,645)	(4)
Proceeds from issuance of warrants	0	0	54,071
Purchases of convertible note hedges	0	0	(128,017)
Repurchases and retirement of common stock	0	0	(55,000)
Proceeds from employee stock plans	107,868	104,160	82,567
Taxes paid related to net share settlement of equity awards	(409,715)	(281,010)	(181,938)
Payments on financing obligations	0	(933)	(4,914)
Net cash (used in) provided by financing activities	(301,856)	(607,428)	538,892
Foreign currency effect on cash, cash equivalents and restricted cash	(186)	(15,530)	28,013
Net increase (decrease) in cash, cash equivalents and restricted cash	209,453	(159,291)	325,897
Cash, cash equivalents and restricted cash at beginning of period	568,538	727,829	401,932
Cash, cash equivalents and restricted cash at end of period	777,991	568,538	727,829
Cash, cash equivalents and restricted cash at end of period:
Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows	777,991	727,829	401,932
Supplemental disclosures of other cash flow information:
Income taxes paid, net of refunds	20,471	17,507	7,899
Non-cash investing and financing activities:
Settlement of 2018 Notes conversion feature	0	773,302	0
Benefit from exercise of 2018 Note Hedge	0	766,858	0
Property and equipment included in accounts payable and accrued expenses	56,966	25,767	15,007
Purchases of intangible assets included in accrued expenses and other liabilities	$ 0	$ 8,500	$ 6,750