Schedule of Total Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total assets	$ 3,272,398	$ 3,271,604
Owned and managed
Segment Reporting Information [Line Items]
Total assets	2,827,928	2,841,799
Managed-only
Segment Reporting Information [Line Items]
Total assets	59,805	62,292
Corporate and Other
Segment Reporting Information [Line Items]
Total assets	$ 384,665	$ 367,513