Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 7,157	$ 21,411
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	5,487	5,161
Loss on disposal and impairment of property and equipment, net	1,563	153
Loss on disposal and abandonment of intangible assets	18	54
Stock-based compensation	16,532	9,047
Deferred income taxes	(1,311)	(58)
Unrecognized tax benefits	613	212
Other noncash, net	1,822	30
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(11,006)	(24,791)
Inventory	(7,515)	4,508
Prepaid expenses and other assets	(5,761)	(7,429)
Accounts payable, accrued and other liabilities	(16,752)	(2,688)
Deferred revenue	6,577	10,496
Net cash provided by (used in) operating activities	(2,576)	16,106
Cash flows from investing activities:
Purchases of investments	(141,992)	(4,331)
Proceeds from maturity/call of investments	25,319	7,038
Purchases of property and equipment	(7,861)	(4,665)
Purchases of intangible assets	(344)	(254)
Business acquisitions	0	(5,014)
Net cash used in investing activities	(124,878)	(7,226)
Cash flows from financing activities:
Net proceeds from equity offering	0	233,993
Proceeds from options exercised	104	586
Income and payroll tax payments for net-settled stock awards	(2,132)	(10,807)
Payment of contingent consideration for a business acquisition	0	(575)
Net cash provided by (used in) financing activities	(2,028)	223,197
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(252)	(538)
Net increase (decrease) in cash, cash equivalents and restricted cash	(129,734)	231,539
Cash, cash equivalents and restricted cash, beginning of period	351,027	78,438
Cash, cash equivalents and restricted cash, end of period	221,293	309,977
Supplemental disclosures:
Cash and cash equivalents	219,720	307,507
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	351,027	78,438
Cash paid for income taxes, net of refunds	1,331	7,758
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	91	665
Non-cash purchase consideration related to business combinations	$ 0	$ 12,288