Unconsolidated Entities - Summary of Amounts Recognized in Consolidated Statements of Income Related to Co-Investment Ventures (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	$ 41,454	$ 41,784	$ 99,765	$ 72,826
Total strategic capital revenue	51,322	47,046	100,988	89,071
Unconsolidated Co-Investment Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	40,934	40,851	88,126	71,087
Total strategic capital revenue	50,748	46,471	99,726	87,774
Total strategic capital revenue and other revenue	53,535	48,017	104,074	90,960
Unconsolidated Co-Investment Ventures [Member] | Development Management and Other Revenue [Member]
Schedule Of Equity Method Investments [Line Items]
Development management and other revenue	2,787	1,546	4,348	3,186
Unconsolidated Co-Investment Ventures [Member] | U.S. [Member]
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	718	669	7,377	961
Total strategic capital revenue	9,179	9,601	18,174	18,161
Unconsolidated Co-Investment Ventures [Member] | Other Americas [Member]
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	7,509	9,091	12,808	13,597
Total strategic capital revenue	5,693	7,013	11,058	12,814
Unconsolidated Co-Investment Ventures [Member] | Europe [Member]
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	29,014	27,306	60,593	48,814
Total strategic capital revenue	25,428	21,001	47,447	39,394
Unconsolidated Co-Investment Ventures [Member] | Asia [Member]
Schedule Of Equity Method Investments [Line Items]
Earnings from unconsolidated entities, net	3,693	3,785	7,348	7,715
Total strategic capital revenue	$ 10,448	$ 8,856	$ 23,047	$ 17,405