Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash, cash equivalents and restricted cash	$ 35,538	$ 69,496
Accounts receivable, net of allowance of $925 in 2022 and $742 in 2021	216,664	205,399
Inventory	49,716	49,204
Prepaid supplies and other	29,233	28,742
TOTAL CURRENT ASSETS	331,151	352,841
Property and equipment, net	2,182,076	2,129,934
Lease incentive	97,115	102,913
Other assets	114,500	113,878
Goodwill and acquired intangibles	501,599	505,125
Operating lease assets	60,488	62,644
Intangibles	105,625	109,151
Goodwill	395,974	395,974
TOTAL ASSETS	3,286,929	3,267,335
CURRENT LIABILITIES:
Accounts payable	187,181	174,237
Accrued salaries, wages and benefits	50,953	56,652
Accrued expenses	12,098	14,950
Current portion of debt obligations	631	628
Current portion of lease obligations	18,840	18,783
Unearned revenue and grants	47,798	47,381
TOTAL CURRENT LIABILITIES	317,501	312,631
Long term debt	1,273,156	1,298,735
Post-retirement obligations	20,623	21,337
Long term lease obligations	42,238	44,387
Other liabilities	51,254	49,662
Stock Warrants	989	915
Deferred income taxes	227,128	217,291
TOTAL LIABILITIES	1,932,889	1,944,958
Commitments and contingencies (Note H)
STOCKHOLDERS’ EQUITY:
Preferred stock, 20,000,000 shares authorized, including 75,000 Series A Junior Participating Preferred Stock	0	0
Common stock, par value $0.01 per share; 150,000,000 shares authorized; 74,337,226 and 74,142,183 shares issued and outstanding in 2022 and 2021, respectively	743	741
Additional paid-in capital	1,035,029	1,074,286
Retained earnings	380,097	309,430
Accumulated other comprehensive loss	(61,829)	(62,080)
TOTAL STOCKHOLDERS’ EQUITY	1,354,040	1,322,377
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 3,286,929	$ 3,267,335