Financial Instruments and Fair Value Measurements - Summary of Gains (Losses) From Change in Fair Value of Derivative Instruments Included in Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total gain on derivative instruments	$ 46,477	$ 115,666	$ 37,437
Total gain on derivative and nonderivative hedging instruments	367,625	436,862	22,527
Designated As Hedging Instrument [Member] | Derivative Net Investment Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total gain on derivative instruments	63,934	122,164	17,847
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total gain on derivative instruments	(21,602)	(804)	(69)
Designated As Hedging Instrument [Member] | Our Share of Derivatives from Unconsolidated Co-Investment Ventures [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total gain on derivative instruments	4,257	(5,694)	19,659
Designated As Hedging Instrument [Member] | Cash Flow Hedge [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total gain on derivative instruments	(112)	0	0
Non-Derivative Net Investment Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Nonderivative net investment hedges	$ 321,148	$ 321,196	$ (14,910)