Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income (loss)	$ (47,917)	$ 4,074
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	4,291	2,881
Loss on disposal and abandonment of intangible assets	11	13
Loss on disposal and impairment of property and equipment, net	45	517
Stock-based compensation	89,610	20,195
Deferred income taxes	(598)	(1,548)
Unrecognized tax benefits	194	341
Other noncash	2,615	1,156
Provision for expected credit losses	(335)	902
Change in assets and liabilities:
Accounts and notes receivable and contract assets	31,298	(9,700)
Inventory	520	(8,630)
Prepaid expenses and other assets	(6,952)	2,277
Accounts payable, accrued and other liabilities	(18,062)	(3,562)
Deferred revenue	6,219	4,499
Net cash provided by operating activities	60,939	13,415
Cash flows from investing activities:
Purchases of investments	(155,825)	(99,512)
Proceeds from call / maturity of investments	132,254	84,315
Purchases of property and equipment	(10,521)	(2,209)
Proceeds from disposal of property and equipment	10	78
Purchases of intangible assets	(41)	(45)
Strategic Investments	(20,000)	(4,700)
Net cash used in investing activities	(54,123)	(22,073)
Cash flows from financing activities:
Proceeds from options exercised	0	28
Income and payroll tax payments for net-settled stock awards	(7,045)	(5,190)
Net cash used in financing activities	(7,045)	(5,162)
Effect of exchange rate changes on cash and cash equivalents	(392)	(1,890)
Net decrease in cash and cash equivalents	(621)	(15,710)
Cash and cash equivalents and restricted cash, beginning of period	155,551	172,355
Cash and cash equivalents and restricted cash, end of period	$ 154,930	$ 156,645