Derivative Instruments - Derivative instruments designated as hedges of the net investment in a foreign operation - Summary (Details) - Derivatives designated as hedging instruments - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Derivative [Line Items]
Weighted average of U.S. dollar equivalent of foreign denominated net assets		$ 2,234,748	$ 628,941
Derivative gains (losses)	[1]	$ (11,515)	$ 66,770

[1] Derivative gains (losses) from derivative instruments designated as hedges of the net investment in a foreign operation are recorded in the cumulative translation adjustment account within AOCI for each period.