Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 9,880	$ 12,578
Marketable securities	17,146	25,141
Accounts receivable, net of allowance for doubtful accounts of $1,656 and $1,596 as of September 30, 2021 and December 31, 2020, respectively	31,955	33,687
Inventories, net	24,639	24,674
Prepaid expenses and other current assets	4,828	3,894
Current contract assets	1,079	1,086
Total current assets	89,527	101,060
Property and equipment, net	59,964	56,273
Intangible assets, net	1,462	2,254
Goodwill	6,562	6,592
Right of use assets	3,609	6,893
Other non-current assets	6,906	7,785
Non-current contract assets	2,322	2,661
Deferred income tax asset	35	73
Total assets	170,387	183,591
Current liabilities:
Accounts payable	9,099	11,400
Accrued compensation and employee-related expenses	6,705	7,156
Accrued other	8,028	6,597
Accrued product warranty costs	1,418	1,812
Current portion of long-term debt	0	4,992
Contract liabilities	4,128	4,445
Current operating lease liability	2,012	3,826
Liability for uncertain tax positions	604	560
Total current liabilities	31,994	40,788
Other long-term liabilities	96	674
Long-term operating lease liability	1,700	3,204
Long-term contract liabilities	4,252	4,688
Long-term debt, excluding current portion	0	1,935
Deferred income tax liability	375	418
Total liabilities	38,417	51,707
Commitments and contingencies (Notes 2, 10, 12, and 18)
Stockholders’ equity:
Preferred stock, $0.01 par value. Authorized 1,000,000 shares; none issued	0	0
Common stock, $0.01 par value. Authorized 30,000,000 shares; 20,331,776 and 19,862,534 shares issued at September 30, 2021 and December 31, 2020, respectively; and 18,899,082 and 18,429,840 shares outstanding at September 30, 2021 and December 31, 2020, respectively	203	199
Additional paid-in capital	155,041	149,170
Accumulated deficit	(8,085)	(2,402)
Accumulated other comprehensive loss	(3,338)	(3,232)
Stockholders equity before treasury stock adjustment	143,821	143,735
Less: treasury stock at cost, common stock, 1,432,694 shares as of September 30, 2021 and December 31, 2020	(11,851)	(11,851)
Total stockholders’ equity	131,970	131,884
Total liabilities and stockholders’ equity	$ 170,387	$ 183,591