Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ (27,558)	$ 13,261
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	8,944	8,196
Loss on disposal and abandonment of intangible assets	252	51
Loss on disposal and impairment of property and equipment, net	1,429	2,408
Stock-based compensation	80,124	30,195
Deferred income taxes	(11,670)	(3,946)
Unrecognized tax benefits	573	594
Other noncash, net	4,573	2,923
Provision for expected credit losses	776	0
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(48,551)	(30,497)
Inventory	(59,371)	(6,302)
Prepaid expenses and other assets	(4,822)	(11,967)
Accounts payable, accrued and other liabilities	25,365	(13,528)
Deferred revenue	34,099	28,476
Net cash provided by operating activities	4,163	19,864
Cash flows from investing activities:
Purchases of investments	(516,687)	(242,693)
Proceeds from call / maturity of investments	287,199	92,207
Purchases of property and equipment	(66,023)	(12,111)
Proceeds from disposal of property and equipment	94	0
Purchases of intangible assets	(177)	(328)
Investment in unconsolidated affiliate	(4,700)	0
Net cash used in investing activities	(300,294)	(162,925)
Cash flows from financing activities:
Net proceeds from equity offering	306,779	0
Proceeds from options exercised	295	106
Income and payroll tax payments for net-settled stock awards	(6,886)	(3,268)
Net cash provided by (used in) financing activities	300,188	(3,162)
Effect of exchange rate changes on cash and cash equivalents	(303)	(678)
Net increase (decrease) in cash and cash equivalents	3,754	(146,901)
Cash and cash equivalents and restricted cash, beginning of period	172,355	351,027
Cash and cash equivalents and restricted cash, end of period	176,109	204,126
Supplemental disclosures:
Cash and cash equivalents	176,000	202,551
Restricted cash (Note 1)	109	1,575
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	176,109	204,126
Cash paid for income taxes, net of refunds	7,678	2,422
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	1,734	1,047
Commission converted to stock-based award	$ 0	$ 314