Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 173,838	$ 216,510
Accounts receivable—net	43,687	38,990
Contract revenues in excess of billings	33,344	32,106
Inventories	30,427	34,689
Prepaid expenses and other current assets	33,121	40,398
Total current assets	314,417	362,693
PROPERTY AND EQUIPMENT—Net	431,856	383,042
OPERATING LEASE ASSETS	52,100	65,188
GOODWILL	76,576	76,576
INVENTORIES—Noncurrent	63,833	58,413
OTHER	12,004	12,112
TOTAL	950,786	958,024
LIABILITIES AND EQUITY
Accounts payable	70,595	71,308
Accrued expenses	41,020	52,899
Operating lease liabilities	14,635	19,472
Billings in excess of contract revenues	18,752	32,608
Total current liabilities	145,002	176,287
LONG-TERM DEBT	320,834	323,735
OPERATING LEASE LIABILITIES—Noncurrent	37,777	45,879
DEFERRED INCOME TAXES	62,229	56,466
OTHER	10,164	8,989
Total liabilities	576,006	611,356
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 65,737 and 65,023 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively.	6	6
Additional paid-in capital	307,065	304,757
Retained earnings	65,662	40,937
Accumulated other comprehensive income	2,047	968
Total equity	374,780	346,668
TOTAL	$ 950,786	$ 958,024