Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (1,724)	$ 882	$ 29,205
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	12,475	11,361	10,615
Loss on disposal and abandonment of intangible assets	320	67	2,117
Loss on disposal and impairment of property and equipment, net	1,722	2,542	303
Stock-based compensation expense	133,572	78,495	21,879
Deferred income taxes	(16,528)	(7,987)	(3,592)
Unrecognized tax benefits	671	983	1,144
Other noncash, net	7,449	3,928	34
Provision for expected credit losses	1,302
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(107,762)	(38,830)	(67,643)
Inventory	(52,156)	(4,903)	14,804
Prepaid expenses and other assets	(14,885)	(9,845)	(12,739)
Accounts payable, accrued and other liabilities	8,886	4,967	13,506
Deferred revenue	65,139	24,013	54,242
Net cash provided by operating activities	38,481	65,673	63,875
Cash flows from investing activities:
Purchases of investments	(656,522)	(354,477)	(4,331)
Proceeds from call / maturity of investments	379,839	130,083	11,158
Purchases of property and equipment	(72,629)	(15,939)	(11,139)
Proceeds from disposal of property and equipment	95
Purchases of intangible assets	(241)	(404)	(558)
Investments in unconsolidated affiliates	(7,068)
Business acquisitions, net of cash acquired			(4,990)
Net cash used in investing activities	(356,526)	(240,737)	(9,860)
Cash flows from financing activities:
Net proceeds from equity offering	306,779		233,993
Proceeds from options exercised	295	114	1,757
Income and payroll tax payments for net-settled stock awards	(7,809)	(4,051)	(14,127)
Payment of contingent consideration for business acquisitions			(2,275)
Net cash provided by (used in) financing activities	299,265	(3,937)	219,348
Effect of exchange rate changes on cash and cash equivalents	1,976	329	(774)
Net increase (decrease) in cash and cash equivalents	(16,804)	(178,672)	272,589
Cash and cash equivalents and restricted cash, beginning of period	172,355	351,027	78,438
Cash and cash equivalents and restricted cash, end of period	$ 155,551	$ 172,355	$ 351,027