ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Schedule of Components) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 1,496,752	$ 1,361,740	$ 1,361,740
Other comprehensive income before reclassifications	13,537		32,431
Amounts reclassified from accumulated other comprehensive income	(1,755)		(1,510)
Net other comprehensive income/(loss)	11,782		30,921
Recapitalization of New Zealand JV			0
Ending balance	1,657,234		1,496,752
Foreign currency translation gains/ (losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	8,559	(2,450)	(2,450)
Other comprehensive income before reclassifications	13,335		7,387
Amounts reclassified from accumulated other comprehensive income	0		0
Net other comprehensive income/(loss)	13,335		7,387
Recapitalization of New Zealand JV			3,622
Ending balance	21,894		8,559
Net investment hedges of New Zealand JV
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1,665	6,271	6,271
Other comprehensive income before reclassifications	0		0
Amounts reclassified from accumulated other comprehensive income	0		(4,606)
Net other comprehensive income/(loss)	0		(4,606)
Recapitalization of New Zealand JV			0
Ending balance	1,665		1,665
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	10,831	(11,592)	(11,592)
Other comprehensive income before reclassifications	202		22,024
Amounts reclassified from accumulated other comprehensive income	(2,104)	223	583
Net other comprehensive income/(loss)	(1,902)		22,607
Recapitalization of New Zealand JV			(184)
Ending balance	8,929		10,831
Cash flow hedges | Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income before reclassifications	(2,900)
Employee benefit plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(20,199)	(25,732)	(25,732)
Other comprehensive income before reclassifications	0		3,020
Amounts reclassified from accumulated other comprehensive income	349		2,513
Net other comprehensive income/(loss)	349		5,533
Recapitalization of New Zealand JV			0
Ending balance	(19,850)		(20,199)
Annual computation of pension liabilities gain (loss)			2,400
Curtailment gain			5,400
Accumulated Other Comprehensive Income/(Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	856	$ (33,503)	(33,503)
Recapitalization of New Zealand JV			3,438
Ending balance	$ 12,638		$ 856