Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 4,074	$ 6,419
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,881	2,800
Loss on disposal and abandonment of intangible assets	13	18
Loss on disposal and impairment of property and equipment, net	517	242
Stock-based compensation	20,195	7,905
Deferred income taxes	(1,548)	577
Unrecognized tax benefits	341	307
Other noncash, net	1,156	896
Provision for expected credit losses	902	0
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(9,700)	(21,994)
Inventory	(8,630)	(3,936)
Prepaid expenses and other assets	2,277	(3,152)
Accounts payable, accrued and other liabilities	(3,562)	(7,284)
Deferred revenue	4,499	3,232
Net cash provided by (used in) operating activities	13,415	(13,970)
Cash flows from investing activities:
Purchases of investments	(99,512)	(105,322)
Proceeds from call / maturity of investments	84,315	0
Purchases of property and equipment	(2,209)	(5,271)
Proceeds from disposal of property and equipment	78	0
Purchases of intangible assets	(45)	(162)
Investment in unconsolidated affiliate	(4,700)	0
Net cash used in investing activities	(22,073)	(110,755)
Cash flows from financing activities:
Proceeds from options exercised	28	100
Income and payroll tax payments for net-settled stock awards	(5,190)	(1,259)
Net cash used in financing activities	(5,162)	(1,159)
Effect of exchange rate changes on cash and cash equivalents	(1,890)	67
Net decrease in cash and cash equivalents	(15,710)	(125,817)
Cash and cash equivalents and restricted cash, beginning of year	172,355	351,027
Cash and cash equivalents and restricted cash, end of year	156,645	225,210
Supplemental disclosures:
Cash and cash equivalents	156,540	223,642
Restricted cash (Note 1)	105	1,568
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	156,645	225,210
Cash paid for income taxes, net of refunds	3,863	758
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	$ 617	$ 328