ACCUMULATED OTHER COMPREHENSIVE LOSS (Summary of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period		$ 3,351,767	$ 3,150,611	$ 3,238,126	$ 3,188,551
Other comprehensive income before reclassifications		(6,406)	2	(25,311)	14,327
Adjustment related to adoption of ASU 2018-02	[1]	0	0	0	(1,148)
Adjustment related to adoption of ASU 2017-12						$ (739)
Net current-period other comprehensive income (loss)		(6,971)	1,935	(27,387)	11,415
Balance at the end of the period		3,380,056	3,181,026	3,380,056	3,181,026
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period		(28,542)	2,515	(8,126)	(6,965)
Adjustment related to adoption of ASU 2018-02					(1,148)
Balance at the end of the period		(35,513)	4,450	(35,513)	4,450
Gain reclassified from accumulated other comprehensive loss to net income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications		199	(394)	(21)	(1,262)
Gain reclassified from accumulated other comprehensive loss to net income | Terminated swap amortization
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications				$ (2,055)	(319)
Pension adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications			2,566		$ 556
Terminated swap amortization
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications		$ (764)	$ (239)

[1] The Company adopted Accounting Standards Update ("ASU") 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, as of January 1, 2018.