Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Write off of Deferred Debt Issuance Cost	$ 6,505	$ 0	$ 0
Withholding taxes paid for conversion of employee stock awards	2,861	2,730	2,438
OPERATING ACTIVITIES:
Net earnings from continuing operations	228,980	25,079	59,983
Net earnings from discontinued operations	2,440	7,036	1,219
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	341,849	310,317	285,353
Pension and post-retirement	7,244	3,888	15,700
Deferred income taxes	70,544	18,492	10,478
Amortization of stock-based compensation	7,386	7,477	7,002
Proceeds from Contributions from Affiliates	2,577	13,587	17,445
Net (gain) loss on financial instruments	(9,800)	5,300	10,000
Changes in assets and liabilities:
Accounts receivable	(51,888)	9,359	(14,551)
Inventory and prepaid supplies	(3,123)	(27,825)	(6,493)
Accounts payable	30,388	5,584	3,340
Unearned revenue	(7,011)	36,922	1,446
Accrued expenses, salaries, wages, benefits and other liabilities	10,059	(5,226)	13,390
Pension and post-retirement balances	(26,884)	(28,198)	(12,132)
Other	(5,530)	(4,036)	2,456
NET CASH PROVIDED BY OPERATING ACTIVITIES	583,557	512,302	396,938
INVESTING ACTIVITIES:
Expenditures for property and equipment	(504,748)	(510,417)	(453,502)
Proceeds from property and equipment	19,427	24,583	10,804
Investment in nonconsolidated affiliate	(2,155)	(13,333)	(24,360)
NET CASH (USED IN) INVESTING ACTIVITIES	(487,476)	(499,167)	(467,058)
FINANCING ACTIVITIES:
Principal payments on long term obligations	(1,900,311)	(689,380)	(39,500)
Proceeds from revolving credit facilities	1,500,600	180,000	100,018
Payments for financing costs	(3,099)	(7,507)	(1,081)
Proceeds from Issuance of Unsecured Debt	207,400	500,000	0
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES	(66,304)	(19,617)	56,999
Proceeds from issuance of warrants	131,967	0	0
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	29,777	(6,482)	(13,121)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	39,719	46,201	59,322
CASH AND CASH EQUIVALENTS AT END OF YEAR	69,496	39,719	46,201
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid, net of amount capitalized	43,696	41,343	57,546
Federal and state income taxes paid	3,431	1,139	1,294
SUPPLEMENTAL NON-CASH INFORMATION:
Accrued expenditures for property and equipment	43,479	37,880	38,396
Net (gain) loss on financial instruments	29,979	(100,771)	(12,302)
Asset Impairment Charges	$ 0	$ 39,075	$ 0