Real Estate Activities - Summary of Operations for Disposed Assets (Detail) - 2018 [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenues		$ 88,838	$ 132,039
Real estate depreciation and amortization		(15,849)	(31,870)
Property-related expenses		(531)	(404)
Other	[1]	709,717	(14,168)
Income from real estate dispositions, net		$ 782,175	$ 85,597

[1] Includes approximately $720 million of gains on sale for the twelve months ended December 31, 2018.