CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 338,008	$ 355,451
Trade receivables, net	86,375	100,987
Unbilled receivables	109,548	102,597
Inventories, net	141,289	145,724
Prepaids and other current assets	42,156	40,790
Total current assets	717,376	745,549
Operating lease right of use assets	4,900	5,258
Property, plant and equipment, net	212,944	216,200
Deferred income taxes	11,021	11,381
Intangible assets	25,684	26,446
Other assets	6,185	5,592
Total assets	978,110	1,010,426
Current liabilities:
Accounts payable	36,599	35,232
Accrued income taxes	3,583	4,102
Contract liabilities	6,504	9,746
Accrued compensation	7,399	6,291
Operating lease liabilities	919	1,046
Other accrued liabilities	15,317	37,246
Total current liabilities	70,321	93,663
Deferred income taxes	4,335	3,925
Income tax payable	9,725	9,627
Operating lease liabilities, long-term	3,965	4,170
Other long-term liabilities	1,989	1,933
Total liabilities	90,335	113,318
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, 35,385,885 and 35,417,712 shares issued and outstanding at March 31, 2022 and December 31, 2021	349	352
Additional paid-in capital	82,781	80,254
Retained earnings	958,344	973,087
Accumulated other comprehensive losses	(153,699)	(156,585)
Total stockholders' equity	887,775	897,108
Total liabilities and stockholders' equity	$ 978,110	$ 1,010,426