OTHER COMPREHENSIVE INCOME (Changes in Accumulated Other Comprehensive Income, Net of Tax) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning balance	$ (197,738)
Other comprehensive income (loss) before reclassifications	(14,679)
Amounts reclassified from AOCI	6,422
Net current period OCI changes	(8,257)
AOCI, Ending balance	(205,995)
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	1,338
Net current period OCI changes	(13,341)
AOCI, Ending balance	(24,294)
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	5,084
Net current period OCI changes	5,084
AOCI, Ending balance	$ (181,701)