ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME (Schedule of Components) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 1,654,550	$ 1,692,940	$ 1,692,940
Other comprehensive (loss) income before reclassifications	(64,074)		(12,979)
Amounts reclassified from accumulated other comprehensive (loss) income	619		(199)
Net other comprehensive (loss) income	(63,455)		(13,178)
Ending balance	1,515,621	1,701,099	1,654,550
Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	239	13,417	13,417
Ending balance	(63,216)	12,348	239
Foreign currency translation (loss) gains
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,010)	15,975	15,975
Other comprehensive (loss) income before reclassifications	(21,545)		(16,985)
Amounts reclassified from accumulated other comprehensive (loss) income	0		0
Net other comprehensive (loss) income	(21,545)		(16,985)
Ending balance	(22,555)		(1,010)
Net investment hedges of New Zealand subsidiary
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1,321	1,665	1,665
Other comprehensive (loss) income before reclassifications	0		(344)
Amounts reclassified from accumulated other comprehensive (loss) income	0		0
Net other comprehensive (loss) income	0		(344)
Ending balance	1,321		1,321
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	21,965	16,184	16,184
Other comprehensive (loss) income before reclassifications	(42,529)		5,944
Amounts reclassified from accumulated other comprehensive (loss) income	282		(163)
Net other comprehensive (loss) income	(42,247)		5,781
Ending balance	(20,282)		21,965
Cash flow hedges | Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive (loss) income before reclassifications	41,000
Employee benefit plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(22,037)	$ (20,407)	(20,407)
Other comprehensive (loss) income before reclassifications	0		(1,594)
Amounts reclassified from accumulated other comprehensive (loss) income	337		(36)
Net other comprehensive (loss) income	337		(1,630)
Ending balance	$ (21,700)		$ (22,037)