Unconsolidated Entities - Summary of Amounts Recognized in Consolidated Statements of Income Related to Co-Investment Ventures (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	$ 57,045	$ 51,003
Total earnings from unconsolidated co-investment ventures, net	48,605	58,311
Unconsolidated Co-Investment Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	55,934	50,315
Total earnings from unconsolidated co-investment ventures, net	45,450	47,192
Unconsolidated Co-Investment Ventures [Member] | U.S. [Member]
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	11,058	8,995
Total earnings from unconsolidated co-investment ventures, net	4,946	6,659
Unconsolidated Co-Investment Ventures [Member] | Other Americas [Member]
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	6,051	5,386
Total earnings from unconsolidated co-investment ventures, net	6,570	5,299
Unconsolidated Co-Investment Ventures [Member] | Europe [Member]
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	26,170	22,333
Total earnings from unconsolidated co-investment ventures, net	29,905	31,579
Unconsolidated Co-Investment Ventures [Member] | Asia [Member]
Schedule Of Equity Method Investments [Line Items]
Total strategic capital revenues	12,655	13,601
Total earnings from unconsolidated co-investment ventures, net	$ 4,029	$ 3,655