OTHER COMPREHENSIVE INCOME (Changes in Accumulated Other Comprehensive Income, Net of Tax) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning balance			$ (197,738)
Other comprehensive income (loss) before reclassifications			(14,679)
Amounts reclassified from AOCI			4,378
Net current period OCI changes	$ 1,889	$ 392	(10,301)	$ 682
AOCI, Ending balance	(208,039)	$ (171,533)	(208,039)	$ (171,533)
Interest Rate Hedge Losses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning balance			(10,953)
Other comprehensive income (loss) before reclassifications			(14,679)
Amounts reclassified from AOCI			988
Net current period OCI changes			(13,691)
AOCI, Ending balance	(24,644)		(24,644)
Pension and Postretirement Plan Actuarial Loss and Prior Service Cost [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning balance			(186,785)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from AOCI			3,390
Net current period OCI changes			3,390
AOCI, Ending balance	$ (183,395)		$ (183,395)