Schedule of Total Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total assets	$ 3,250,632	$ 3,127,191
Owned and managed
Segment Reporting Information [Line Items]
Total assets	2,852,712	2,745,905
Managed-only
Segment Reporting Information [Line Items]
Total assets	65,588	68,146
Corporate and Other
Segment Reporting Information [Line Items]
Total assets	$ 332,332	$ 313,140