Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 114,747	$ 129,625
Restricted cash	640	658
Short-term investments	214,635	189,771
Accounts receivable, net	108,312	79,991
Contract assets	14,084	21,246
Inventories	164,041	145,906
Deferred cost of sales	595	433
Prepaid expenses and other current assets	21,570	19,301
Total current assets	638,624	586,931
Property, plant, and equipment, net	82,208	65,271
Operating lease right-of-use assets	27,768	10,275
Intangible assets, net	39,855	46,185
Goodwill	181,943	181,943
Deferred income taxes	1,440	1,440
Other assets	3,671	6,019
Total assets	975,509	898,064
Current liabilities:
Accounts payable	55,045	33,656
Accrued expenses and other current liabilities	52,436	44,876
Customer deposits and deferred revenue	70,569	67,235
Income taxes payable	1,363	914
Total current liabilities	179,413	146,681
Deferred income taxes	5,257	5,240
Long-term debt	328,215	321,115
Long-term operating lease liabilities	31,036	6,305
Other liabilities	7,853	10,349
Total liabilities	551,774	489,690
Stockholders' equity:
Preferred stock, $0.01 par value; 500,000 shares authorized; no shares issued and outstanding.
Common stock, $0.01 par value; 120,000,000 shares authorized; 50,348,804 shares issued and outstanding at June 30, 2021 and 49,723,751 shares issued and outstanding at December 31, 2020	503	497
Additional paid-in capital	1,119,908	1,113,352
Accumulated deficit	(698,479)	(707,321)
Accumulated other comprehensive income	1,803	1,846
Total stockholders' equity	423,735	408,374
Total liabilities and stockholders' equity	$ 975,509	$ 898,064