Derivatives and Hedge Accounting - Summary of Effect of Foreign Currency Exchange Contracts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Effect of net investment hedges on accumulated other comprehensive loss	$ (580)	$ 0	$ (580)	$ 0
Gain/(Loss) recognized in unaudited consolidated statements of income	1,202	1,414	2,462	2,029
Foreign currency exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Effect of net investment hedges on accumulated other comprehensive loss	(580)	0	(580)	0
Derivatives in cash flow hedging relationships | Derivatives in hedging relationships | Foreign currency exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Effect of net investment hedges on accumulated other comprehensive loss	3,288	(12,229)	9,225	(17,243)
Reclassification out of Accumulated Other Comprehensive Income | Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) recognized in unaudited consolidated statements of income	$ 2,923	$ (2,641)	$ 4,319	$ (5,569)