Segment Information - Summary of Information about Company's Reportable Operating Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 257,321	$ 257,323	$ 511,744	$ 516,148
Rental operation expenses	(71,864)	(73,826)	(144,906)	(150,181)
Net operating income (loss)	185,457	183,497	366,838	365,967
Impairment charges			0	(279,021)
Depreciation and amortization	(97,698)	(99,300)	(194,600)	(202,315)
Interest income	9,446	7,211	18,496	14,372
Other income (expense), net	2,081	2,368	3,854	(1,060)
Unallocated expenses	(72,756)	(81,131)	(148,987)	(167,646)
Equity in net income of joint ventures	1,117	1,642	15,538	1,703
Gain (Loss) on sale and change in control of interests, net	0	(6,507)	0	7,772
Income (loss) from continuing operations	27,647	7,780	61,139	(260,228)
Total gross real estate assets	9,949,961	10,180,374	9,949,961	10,180,374
Notes receivable, net	47,294	47,304	47,294	47,304	$ 42,534
Operating Segments [Member] | Shopping Center [Member]
Segment Reporting Information [Line Items]
Total revenues	257,310	257,283	511,727	516,053
Rental operation expenses	(71,747)	(73,809)	(144,750)	(150,145)
Net operating income (loss)	185,563	183,474	366,977	365,908
Impairment charges				(279,021)
Depreciation and amortization	(97,698)	(99,300)	(194,600)	(202,315)
Equity in net income of joint ventures	1,117	1,642	15,538	1,703
Gain (Loss) on sale and change in control of interests, net		(6,507)		7,772
Total gross real estate assets	9,949,961	10,180,374	9,949,961	10,180,374
Operating Segments [Member] | Loan Investments [Member]
Segment Reporting Information [Line Items]
Total revenues	11	40	17	95
Rental operation expenses	(117)	(17)	(156)	(36)
Net operating income (loss)	(106)	23	(139)	59
Interest income	9,446	7,211	18,496	14,372
Notes receivable, net	447,074	355,911	447,074	355,911
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Other income (expense), net	2,081	2,368	3,854	(1,060)
Unallocated expenses	(72,756)	(81,131)	(148,987)	(167,646)
Notes receivable, net	$ (399,780)	$ (308,607)	$ (399,780)	$ (308,607)