Investments in and Advances to Joint Ventures - Condensed Combined Statements of Operations of Unconsolidated Joint Venture Investments (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expenses from operations:
Operating expenses		$ 1,033,385	$ 853,610	$ 1,048,141
Impairment charges	$ 280,100	340,480	110,906	279,021
Depreciation and amortization		346,204	389,519	402,045
Interest expense		188,647	217,589	241,727
Other (income) expense, net		68,003	(3,322)	1,739
Loss from continuing operations		(404,296)	(12,187)	(237,881)
Gain on disposition of real estate, net		161,164	73,386	167,571
Company's share of equity in net income (loss) of joint ventures		3,516	11,650	(5,289)
Basis differential adjustments		5,321	4,049	2,154
Equity in net income (loss) of joint ventures		8,837	15,699	(3,135)
Unconsolidated Joint Ventures [Member]
Condensed Combined Statements of Operations
Revenues from operations		502,506	513,365	524,697
Expenses from operations:
Operating expenses		145,855	144,984	146,924
Impairment charges		90,597	13,598	52,700
Depreciation and amortization		180,337	195,198	207,816
Interest expense		107,330	132,943	140,701
Preferred share expense		32,251	33,418	25,991
Other (income) expense, net		25,986	23,513	30,235
Total expenses		582,356	543,654	604,367
Loss from continuing operations		(79,850)	(30,289)	(79,670)
Gain on disposition of real estate, net		101,806	57,261	17,188
Net income (loss) attributable to unconsolidated joint ventures		$ 21,956	$ 26,972	$ (62,482)