Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income and Other Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
AOCI Rollforward
Beginning of Period	$ 1,463,962
Other comprehensive (loss) income:
Foreign currency translation adjustment	(222,305)	$ 17,378
Change in fair value of derivative instruments	(8,362)	(2,674)
Total other comprehensive (loss) income	(230,667)	14,704
End of Period	1,123,675
Foreign Currency Translation Adjustments
AOCI Rollforward
Beginning of Period	(252,825)	(264,691)
Other comprehensive (loss) income:
Foreign currency translation adjustment	(222,305)	17,378
Change in fair value of derivative instruments	0	0
Total other comprehensive (loss) income	(222,305)	17,378
End of Period	(475,130)	(247,313)
Change in Fair Value of Derivative Instruments
AOCI Rollforward
Beginning of Period	(9,756)	(973)
Other comprehensive (loss) income:
Foreign currency translation adjustment	0	0
Change in fair value of derivative instruments	(8,362)	(2,674)
Total other comprehensive (loss) income	(8,362)	(2,674)
End of Period	(18,118)	(3,647)
Total
AOCI Rollforward
Beginning of Period	(262,581)	(265,664)
Other comprehensive (loss) income:
End of Period	$ (493,248)	$ (250,960)

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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