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	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total derivative instruments	$ 13,932	$ 15,586	$ 18,857	$ 7,602
Total derivative and nonderivative hedging instruments	(215,734)	107,002	(255,335)	(62,171)
Designated As Hedging Instrument [Member] | Derivative Net Investment Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total derivative instruments	7,197	21,512	9,491	29,420
Designated As Hedging Instrument [Member] | Interest Rate and Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total derivative instruments	4,559	(2,703)	4,988	(13,824)
Designated As Hedging Instrument [Member] | Our Share of Derivatives from Unconsolidated Co-Investment Ventures [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total derivative instruments	2,176	(3,223)	4,378	(7,994)
Non-Derivative Net Investment Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Nonderivative net investment hedges	$ (229,666)	$ 91,416	$ (274,192)	$ (69,773)