PENSION PLANS AND OTHER POST-RETIREMENT BENEFITS - Defined Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amounts recognized in the consolidated balance sheets
Long-term liabilities	$ (214,671)	$ (214,671)	$ (300,373)
Components of net periodic pension costs
Plan settlement	5,900
Defined Benefit Plans
Change in benefit obligation
Benefit obligation at the beginning of the year		826,120	759,821
Service cost				$ 50
Interest cost		22,758	25,971	30,327
Actuarial loss (gain)		(19,218)	75,131
Benefits paid		(36,381)	(34,803)
Plan settlement		(48,816)
Benefit obligation at the end of the year	744,463	744,463	826,120	759,821
Change in plan assets
Fair value of plan assets at the beginning of the year		623,826	556,967
Employer contributions		20,755	24,039
Actual return on plan assets		58,156	77,623
Benefits paid		(36,381)	(34,803)
Plan settlement		(48,816)
Fair value of plan assets at the end of the year	617,540	617,540	623,826	556,967
Funded status at year end	(126,923)	(126,923)	(202,294)
Amounts recognized in the consolidated balance sheets
Current liabilities	(242)	(242)	(244)
Long-term liabilities	(126,681)	(126,681)	(202,050)
Amounts recognized in accumulated other comprehensive loss
Unamortized prior service cost (credit)	808	808	930
Unamortized net actuarial loss (gain)	90,318	90,318	138,868
Total	$ 91,126	91,126	139,798
Components of net periodic pension costs
Service cost				50
Interest cost		22,758	25,971	30,327
Expected return on plan assets		(36,997)	(34,544)	(34,627)
Net amortization loss (gain)		2,309	1,165	2,890
Net prior service cost (credit) amortization		122	123	123
Plan settlement		5,864		6,726
Net periodic pension cost (benefit)		(5,944)	(7,285)	$ 5,489
Changes in plan assets and benefit obligations recognized in other comprehensive loss, before tax effects
Actuarial loss (gain), net		(40,377)	32,052
Recognized actuarial gain (loss)		(2,309)	(1,165)
Recognized prior service (cost) credit		(122)	(123)
Plan settlement		(5,864)
Total amount recognized in other comprehensive loss, before tax effects		$ (48,672)	$ 30,764
Weighted-average assumptions used to determine the projected benefit obligations and net periodic benefit cost
Discount rate - net periodic benefit cost (as a percent)		2.81%	3.51%	4.36%
Discount rate - benefit obligation (as a percent)	3.05%	3.05%	2.81%	3.51%
Expected long-term rate of return on plan assets (as a percent)		6.00%	6.25%	6.97%
Rate of compensation/salary increase (as a percent)			2.50%	2.50%
Interest crediting rate for cash balance plans (as a percent)		2.00%	2.00%	3.00%
Post-retirement Benefit Obligations
Change in benefit obligation
Benefit obligation at the beginning of the year		$ 106,704	$ 107,132
Service cost		649	825	$ 957
Interest cost		2,579	3,265	4,231
Plan participant contributions		868	218
Actuarial loss (gain)		(4,860)	6,387
Benefits paid		(9,506)	(9,376)
Plan amendments			(1,747)
Benefit obligation at the end of the year	$ 96,434	96,434	106,704	107,132
Change in plan assets
Fair value of plan assets at the beginning of the year		3,337	3,164
Employer contributions		8,638	9,159
Plan participant contributions		868	218
Actual return on plan assets		209	172
Benefits paid		(9,506)	(9,376)
Fair value of plan assets at the end of the year	3,546	3,546	3,337	3,164
Funded status at year end	(92,888)	(92,888)	(103,367)
Amounts recognized in the consolidated balance sheets
Current liabilities	(5,446)	(5,446)	(5,709)
Long-term liabilities	(87,442)	(87,442)	(97,658)
Amounts recognized in accumulated other comprehensive loss
Unamortized prior service cost (credit)	(2,865)	(2,865)	(3,766)
Unamortized net actuarial loss (gain)	(4,585)	(4,585)	284
Total	$ (7,450)	(7,450)	(3,482)
Components of net periodic pension costs
Service cost		649	825	957
Interest cost		2,579	3,265	4,231
Expected return on plan assets		(200)	(197)	(180)
Net amortization loss (gain)			(1,859)	(2,033)
Net prior service cost (credit) amortization		(901)	1,147	3,072
Net periodic pension cost (benefit)		2,127	3,181	$ 6,047
Changes in plan assets and benefit obligations recognized in other comprehensive loss, before tax effects
Actuarial loss (gain), net		(4,869)	6,412
Recognized actuarial gain (loss)			1,859
Prior service credit			(1,747)
Recognized prior service (cost) credit		901	(1,147)
Total amount recognized in other comprehensive loss, before tax effects		$ (3,968)	$ 5,377
Weighted-average assumptions used to determine the projected benefit obligations and net periodic benefit cost
Discount rate - net periodic benefit cost (as a percent)		2.57%	3.35%	4.35%
Discount rate - benefit obligation (as a percent)	2.93%	2.93%	2.56%	3.34%
Rate of compensation/salary increase (as a percent)		2.50%	2.50%	2.50%