Derivative Instruments - Summary of Unrealized Gain (Loss) Recorded In and Reclassified From Accumulated Other Comprehensive Income (Details) - Derivatives designated as hedging instruments: - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Comprehensive Income (Effective Portion)	$ (560)	$ 525	$ 11,776	$ 6,625
Loss Reclassified from AOCI to Income (Effective Portion)	950	(972)	912	(6,705)
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Comprehensive Income (Effective Portion)	(1,938)	525	7,307	6,625
Interest rate swaps | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Loss Reclassified from AOCI to Income (Effective Portion)	950	(972)	912	(6,705)
Net investment cross currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Comprehensive Income (Effective Portion)	1,378	0	4,469	0
Loss Reclassified from AOCI to Income (Effective Portion)	$ 0	$ 0	$ 0	$ 0