SHAREHOLDERS' EQUITY - Reclassification from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
EQUITY
Settlement loss	$ (5,900)
Income (loss) before income taxes		$ (100,414)	$ 48,238	$ (23,645)
Interest expense		(175,195)	(143,591)	(136,660)
Tax benefit (expense)		(6,279)	(10,936)	3,714
Net income (loss)		(106,693)	37,302	$ (19,931)
Pension and Post-Retirement Obligations
EQUITY
Prior service credit (cost)		779	(1,270)
Actuarial gain (loss)		(2,309)	694
Settlement loss		(5,864)
Income (loss) before income taxes		(7,394)	(576)
Tax benefit (expense)		1,950	140
Net income (loss)		(5,444)	(436)
Derivative Instruments
EQUITY
Interest expense		(13,964)	(15,683)
Tax benefit (expense)		3,773	4,061
Net income (loss)		$ (10,191)	$ (11,622)