CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 235,343	$ 264,804
Short term investments	18,921	32,232
Trade receivables, net	132,206	91,504
Unbilled receivables	150,290	144,428
Inventories, net	152,770	146,004
Prepaid expenses	15,592	19,874
Other current assets	36,161	34,359
Assets held for sale	10,828	19,383
Total current assets	752,111	752,588
Operating lease right of use assets	6,325	4,872
Property, plant and equipment, net	183,285	181,270
Deferred income taxes	4,850	4,488
Intangible assets	22,691	23,348
Other assets	6,134	5,949
Total assets	975,396	972,515
Current liabilities:
Accounts payable	47,212	43,019
Accrued income taxes	5,677	4,868
Contract liabilities	7,271	8,020
Accrued compensation	7,578	5,796
Operating lease liabilities	1,230	1,054
Other accrued liabilities	14,392	24,798
Total current liabilities	83,360	87,555
Deferred income taxes	4,025	3,756
Income tax payable	874	823
Operating lease liabilities, long-term	5,178	3,807
Other long-term liabilities	1,581	1,658
Total liabilities	95,018	97,599
Contingencies (Note 12)
Stockholders' equity:
Preferred stock: 10,000,000 shares authorized at $0.01 par value (none issued)	0	0
Common stock:
100,000,000 shares authorized at $0.01 par value, 34,171,856 and 34,157,057 shares issued and outstanding at March 31, 2023 and December 31, 2022	343	343
Additional paid-in capital	93,027	90,450
Retained earnings	955,043	952,732
Accumulated other comprehensive losses	(168,035)	(168,609)
Total stockholders' equity	880,378	874,916
Total liabilities and stockholders' equity	$ 975,396	$ 972,515