Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash Flows from Operating Activities
Net income	$ 22,985	$ 8,842
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	12,749	13,189
Non-cash interest expense	477	7,100
Deferred income taxes	(18)	17
Share-based compensation expense	10,759	7,605
Changes in operating assets and liabilities:
Accounts receivable and contract assets	(16,346)	(21,158)
Inventories	(5,873)	(18,298)
Prepaid expenses and other current assets	8,231	4,489
Accounts payable and accrued expenses	(17,613)	14,046
Customer deposits and deferred revenue	11,424	3,334
Income taxes receivable and payable, net	(263)	449
Other, net	1,657	1,114
Net cash provided by (used in) operating activities	28,169	20,729
Cash Flows from Investing Activities
Capital expenditures	(15,420)	(9,082)
Proceeds from the sale of investments	23,335	130,398
Payments for purchases of investments	(33,876)	(156,020)
Net cash provided by (used in) investing activities	(25,961)	(34,704)
Cash Flows from Financing Activities
Proceeds (net of tax withholdings) from option exercises and employee stock purchase plan	2,129	1,865
Restricted stock tax withholdings	(7,115)	(2,747)
Net cash provided by (used in) financing activities	(4,986)	(882)
Effect of exchange rate changes on cash and cash equivalents	(51)	(39)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(2,829)	(14,896)
Cash, cash equivalents, and restricted cash - beginning of period	120,472	130,283
Cash, cash equivalents, and restricted cash - end of period	117,643	115,387
Supplemental Disclosure of Cash Flow Information
Interest paid	5,037	4,160
Income taxes paid (refunds received)	1,083	(196)
Non-cash activities
Capital expenditures included in accounts payable and accrued expenses	6,464	15,400
Net transfer of inventory to property, plant and equipment	237
Right-of-use assets obtained in exchange for lease obligations	$ 258	$ 20,353