Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 882	$ 29,205	$ 5,207
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,361	10,615	8,041
Loss on disposal and abandonment of intangible assets	67	2,117	1,146
Purchase accounting adjustments to goodwill	0	0	(23)
Loss (gain) on disposal and impairment of property and equipment, net	2,542	303	(28)
Stock-based compensation	78,495	21,879	15,610
Deferred income taxes	(7,987)	(3,592)	2,830
Unrecognized tax benefits	983	1,144	(191)
Other noncash, net	3,928	34	657
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(38,830)	(67,643)	(35,305)
Inventory	(4,903)	14,804	(11,746)
Prepaid expenses and other assets	(9,845)	(12,739)	(8,992)
Accounts payable, accrued and other liabilities	4,967	13,506	1,530
Deferred revenue	24,013	54,242	39,735
Net cash provided by operating activities	65,673	63,875	18,471
Cash flows from investing activities:
Purchases of investments	(354,477)	(4,331)	(19,950)
Proceeds from call / maturity of investments	130,083	11,158	61,080
Purchases of property and equipment	(15,939)	(11,139)	(10,419)
Proceeds from disposal of property and equipment	0	0	24
Purchases of intangible assets	(404)	(558)	(1,024)
Business acquisitions, net of cash acquired	0	(4,990)	(10,629)
Net cash provided by (used in) investing activities	(240,737)	(9,860)	19,082
Cash flows from financing activities:
Net proceeds from equity offering	0	233,993	0
Proceeds from options exercised	114	1,757	1,383
Income and payroll tax payments for net-settled stock awards	(4,051)	(14,127)	(3,453)
Payment of contingent consideration for business acquisitions	0	(2,275)	(1,750)
Net cash provided by (used in) financing activities	(3,937)	219,348	(3,820)
Effect of exchange rate changes on cash and cash equivalents	329	(774)	737
Net increase (decrease) in cash and cash equivalents	(178,672)	272,589	34,470
Cash and cash equivalents and restricted cash, beginning of year	351,027	78,438	43,968
Cash and cash equivalents and restricted cash, end of year	$ 172,355	$ 351,027	$ 78,438