Summary of Cash Flows of Discontinued Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 12,925	$ 16,247
Cash paid (refunds received) for taxes	(2)	24
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	$ (293)	(3,813)
Non-cash increase (decrease) in indebtedness from deconsolidation of properties		$ (27,467)