ACCUMULATED OTHER COMPREHENSIVE LOSS (Summary of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period		$ 3,307,473	$ 3,079,363	$ 3,238,126	$ 3,188,551
Other comprehensive income before reclassifications		(13,038)	6,054	(18,905)	14,325
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)		(13,783)	3,312	(20,416)	9,480
Balance at the end of the period		3,351,767	3,150,611	3,351,767	3,150,611
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period		(14,759)	(797)	(8,126)	(6,965)
Adjustment related to adoption of ASU 2018-02					(1,148)
Balance at the end of the period		(28,542)	2,515	(28,542)	2,515
Gain reclassified from accumulated other comprehensive loss to net income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications		(92)	(652)	(220)	(868)
Gain reclassified from accumulated other comprehensive loss to net income | Terminated swap
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications		$ (653)	(80)	$ (1,291)	(80)
Pension adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassifications			$ (2,010)		$ (2,010)

[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.