Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash, cash equivalents and restricted cash	$ 47,151	$ 69,496
Accounts receivable, net of allowance of $902 in 2022 and $742 in 2021	260,260	205,399
Inventory	54,005	49,204
Prepaid supplies and other	28,157	28,742
TOTAL CURRENT ASSETS	389,573	352,841
Property and equipment, net	2,270,656	2,129,934
Lease incentive	91,293	102,913
Other assets	145,800	113,878
Goodwill and acquired intangibles	498,073	505,125
Operating lease assets	64,155	62,644
Intangibles	102,099	109,151
Goodwill	395,974	395,974
TOTAL ASSETS	3,459,550	3,267,335
CURRENT LIABILITIES:
Accounts payable	194,951	174,237
Accrued salaries, wages and benefits	62,538	56,652
Accrued expenses	11,423	14,950
Current portion of debt obligations	634	628
Current portion of lease obligations	20,497	18,783
Unearned revenue and grants	38,293	47,381
TOTAL CURRENT LIABILITIES	328,336	312,631
Long term debt	1,358,842	1,298,735
Post-retirement obligations	20,375	21,337
Long term lease obligations	44,305	44,387
Other liabilities	53,596	49,662
Stock Warrants	851	915
Deferred income taxes	241,752	217,291
TOTAL LIABILITIES	2,048,057	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; 74,369,138 and 74,142,183 shares issued and outstanding in 2022 and 2021, respectively	744	741
Additional paid-in capital	1,037,139	1,074,286
Retained earnings	435,189	309,430
Accumulated other comprehensive loss	(61,579)	(62,080)
TOTAL STOCKHOLDERS’ EQUITY	1,411,493	1,322,377
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 3,459,550	$ 3,267,335