Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash, cash equivalents and restricted cash	$ 39,719	$ 46,201
Accounts receivable, net of allowance of $997 in 2020 and $975 in 2019	153,511	162,870
Inventory	40,410	37,397
Prepaid supplies and other	39,096	20,323
TOTAL CURRENT ASSETS	272,736	266,791
Property and equipment, net	1,939,776	1,766,020
Lease incentive	126,007	146,678
Other assets	78,112	68,733
Goodwill and acquired intangibles	516,290	527,654
Operating lease assets	68,824	44,302
Intangibles	120,316	131,680
Goodwill	395,974	395,974
TOTAL ASSETS	3,001,745	2,820,178
CURRENT LIABILITIES:
Accounts payable	141,425	141,094
Accrued salaries, wages and benefits	56,506	59,429
Accrued expenses	19,005	17,586
Current portion of debt obligations	13,746	14,707
Current portion of lease obligations	17,784	12,857
Unearned revenue and grants	53,522	17,566
TOTAL CURRENT LIABILITIES	301,988	263,239
Long term debt	1,465,331	1,469,677
Post-retirement obligations	35,099	36,744
Long term lease obligations	51,128	30,334
Other liabilities	47,963	49,293
Stock Warrants	103,474	383,073
Deferred income taxes	141,265	127,476
TOTAL LIABILITIES	2,146,248	2,359,836
Commitments and contingencies (Note I)
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; 59,560,036 and 59,329,431 shares issued and outstanding in 2020 and 2019, respectively	596	593
Additional paid-in capital	855,547	475,720
Retained earnings	78,010	45,895
Accumulated other comprehensive loss	(78,656)	(61,866)
TOTAL STOCKHOLDERS’ EQUITY	855,497	460,342
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 3,001,745	$ 2,820,178