CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 345,955	$ 398,946
Trade receivables, net	116,202	107,626
Unbilled receivables	140,318	140,534
Inventories, net	212,536	205,062
Prepaids and other current assets	48,182	28,321
Total current assets	863,193	880,489
Operating lease right of use assets	6,962	5,144
Property, plant and equipment, net	234,823	258,497
Deferred income taxes	5,768	8,936
Goodwill		7,947
Intangible assets	29,434	32,245
Other assets	10,992	13,307
Total assets	1,151,172	1,206,565
Current liabilities:
Accounts payable	37,424	46,324
Accrued income taxes	4,343	4,561
Contract liabilities	11,339	6,901
Accrued compensation	5,015	13,599
Operating lease liabilities	1,110	1,314
Other accrued liabilities	26,281	24,241
Total current liabilities	85,512	96,940
Deferred income taxes	6,779	4,150
Income tax payable	9,383	8,868
Operating lease liabilities, long-term	5,845	3,801
Other long-term liabilities	2,125	2,105
Total liabilities	109,644	115,864
Contingencies (Note 15)
Stockholders' equity:
Preferred stock: 10,000,000 shares authorized at $0.01 par value (none issued)
Common stock:
100,000,000 shares authorized at $0.01 par value, 35,417,712 and 35,859,540 shares issued and outstanding at December 31, 2020 and December 31, 2019	363	371
Additional paid-in capital	65,613	52,870
Retained earnings	1,125,263	1,181,023
Accumulated other comprehensive losses	(149,711)	(143,563)
Total stockholders' equity	1,041,528	1,090,701
Total liabilities and stockholders' equity	$ 1,151,172	$ 1,206,565