Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 207,474	$ 186,995
Accounts receivable—net	44,014	19,785
Contract revenues in excess of billings	37,080	22,560
Inventories	29,440	30,189
Prepaid expenses and other current assets	32,300	41,183
Total current assets	350,308	300,712
PROPERTY AND EQUIPMENT—Net	371,884	374,596
OPERATING LEASE ASSETS	81,319	72,612
GOODWILL	76,576	76,576
INVENTORIES—Noncurrent	64,090	61,126
ASSETS HELD FOR SALE— Noncurrent	3,970	3,970
OTHER	7,732	7,960
TOTAL	955,879	897,552
LIABILITIES AND EQUITY
Accounts payable	79,917	76,091
Accrued expenses	53,898	51,225
Operating lease liabilities	20,965	21,351
Billings in excess of contract revenues	61,327	55,266
Total current liabilities	216,107	203,933
LONG-TERM DEBT	323,066	322,843
OPERATING LEASE LIABILITIES—Noncurrent	60,641	51,131
DEFERRED INCOME TAXES	44,633	35,740
OTHER	4,803	4,506
Total liabilities	649,250	618,153
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 64,795 and 64,283 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively.	6	6
Additional paid-in capital	302,558	302,189
Retained earnings (accumulated deficit)	10,896	(23,091)
Accumulated other comprehensive income (loss)	(6,831)	295
Total equity	306,629	279,399
TOTAL	$ 955,879	$ 897,552