Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 13,261	$ 27,122
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,196	8,226
Loss on disposal and impairment of property and equipment, net	2,408	290
Loss on disposal and abandonment of intangible assets	51	2,103
Stock-based compensation	30,195	15,302
Deferred income taxes	(3,946)	(2,326)
Unrecognized tax benefits	594	99
Other noncash, net	2,923	34
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(30,497)	(51,172)
Inventory	(6,302)	9,033
Prepaid expenses and other assets	(11,967)	(12,081)
Accounts payable, accrued and other liabilities	(13,528)	4,306
Deferred revenue	28,476	31,700
Net cash provided by operating activities	19,864	32,636
Cash flows from investing activities:
Purchases of investments	(242,693)	(4,331)
Proceeds from maturity/call of investments	92,207	10,658
Purchases of property and equipment	(12,111)	(6,880)
Purchases of intangible assets	(328)	(460)
Business acquisitions	0	(4,990)
Net cash used in investing activities	(162,925)	(6,003)
Cash flows from financing activities:
Net proceeds from equity offering	0	233,993
Proceeds from options exercised	106	713
Income and payroll tax payments for net-settled stock awards	(3,268)	(11,973)
Payment of contingent consideration for a business acquisition	0	(575)
Net cash provided by (used in) financing activities	(3,162)	222,158
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(678)	(381)
Net increase (decrease) in cash, cash equivalents and restricted cash	(146,901)	248,410
Cash, cash equivalents and restricted cash, beginning of period	351,027	78,438
Cash, cash equivalents and restricted cash, end of period	204,126	326,848
Supplemental disclosures:
Cash and cash equivalents	202,551	324,371
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	2,422	7,957
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	1,047	1,114
Non-cash purchase consideration related to business combinations	0	12,508
Commission converted to stock-based award	$ 314	$ 0