Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 180,767	$ 216,510
Accounts receivable—net	35,741	38,990
Contract revenues in excess of billings	34,556	32,106
Inventories	32,758	34,689
Prepaid expenses and other current assets	39,330	40,398
Total current assets	323,152	362,693
PROPERTY AND EQUIPMENT—Net	422,552	383,042
OPERATING LEASE ASSETS	52,777	65,188
GOODWILL	76,576	76,576
INVENTORIES—Noncurrent	61,578	58,413
OTHER	12,998	12,112
TOTAL	949,633	958,024
LIABILITIES AND EQUITY
Accounts payable	79,863	71,308
Accrued expenses	37,230	52,899
Operating lease liabilities	14,255	19,472
Billings in excess of contract revenues	28,833	32,608
Total current liabilities	160,181	176,287
LONG-TERM DEBT	320,696	323,735
OPERATING LEASE LIABILITIES—Noncurrent	38,877	45,879
DEFERRED INCOME TAXES	59,458	56,466
OTHER	10,324	8,989
Total liabilities	589,536	611,356
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 65,654 and 65,023 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively.	6	6
Additional paid-in capital	304,977	304,757
Retained earnings	51,856	40,937
Accumulated other comprehensive income	3,258	968
Total equity	360,097	346,668
TOTAL	$ 949,633	$ 958,024