OTHER COMPREHENSIVE INCOME (Changes in Accumulated Other Comprehensive Income, Net of Tax) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
AOCI, Beginning balance	$ (149,466)
Other comprehensive income (loss) before reclassifications	2,496
Amounts reclassified from AOCI	1,157
Other comprehensive income	3,653	$ 747
AOCI, Ending balance	(145,813)	$ (138,629)
Amortization of Interest Rate Hedge Losses [Member]
AOCI, Beginning balance	(11,438)
Other comprehensive income (loss) before reclassifications	2,496
Amounts reclassified from AOCI	66
Other comprehensive income	2,562
AOCI, Ending balance	(8,876)
Amortization of Pension and Postretirement Plan Actuarial Loss and Prior Service Cost [Member]
AOCI, Beginning balance	(138,028)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from AOCI	1,091
Other comprehensive income	1,091
AOCI, Ending balance	$ (136,937)