CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities
Net income (loss)	$ (141,196)	$ (41,420)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	11,746	5,696
Share-based compensation	81,024	694
Other	2,719	(993)
Changes in assets and liabilities:
Accounts receivable	100,991	61,329
Prepaid expenses and other assets	6,624	510
Operating lease right-of-use assets	10,879	6,427
Accounts payable	2,613	7,481
Accrued expenses and other liabilities	(4,905)	(2,024)
Operating lease liabilities	(13,205)	(4,578)
Net cash provided by operating activities	57,290	33,122
Investing activities
Purchases of property and equipment and intangible assets	(7,005)	(3,706)
Purchases of marketable securities	(257,593)	(113,952)
Sales of marketable securities	72,043	28,953
Maturities of marketable securities	250,074	84,883
Other investing activities	316	0
Net cash provided by (used in) investing activities	57,835	(3,822)
Financing activities
Proceeds from exercise of stock options, net	20,347	110
Shares repurchased for tax withholdings on release of restricted stock units	(44,090)	0
Other financing activities	0	(3,279)
Net cash used in financing activities	(23,743)	(3,169)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(214)	8
Net increase in cash, cash equivalents, and restricted cash	91,168	26,139
Cash, cash equivalents, and restricted cash, beginning of period	677,743	135,290
Cash, cash equivalents, and restricted cash, end of period	768,911	161,429
Supplemental cash flow information
Accrued property and equipment	7,831	4,484
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	$ 1,242	$ 22,862