EQUITY - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ 3,407,925	$ 3,437,249	$ 996,715	$ 1,015,609
Total accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	24,412	11,289	$ (833)	$ (1,798)
Foreign currency translation loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(3,026)	(2,913)
Unrealized gains on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ 27,438	$ 14,202