Summary of Cash Flows of Discontinued Operations (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flow Supplemental Disclosures [Line Items]
Cash paid for interest	$ 28,483	$ 31,498
Cash paid (refunds received) for taxes	(1)	203
Non-cash increase in investments in real estate, intangible assets, and other liabilities from conversion of loans		1,590
Non-cash (decrease) in investments in real estate, restricted cash, other assets, intangible assets, accounts payable and accrued expenses, and other liabilities from deconsolidation of properties		(43,025)
Non-cash increase (decrease) in indebtedness from debt extinguishments	$ (1,265)	(3,813)
Non-cash increase (decrease) in indebtedness from deconsolidation of properties		(27,467)
South Terrace
Cash Flow Supplemental Disclosures [Line Items]
Non-cash increase (decrease) to noncontrolling interests from distribution of limited partnership units on South Terrace		$ (1,618)