Combined Guarantor Subsidiaries - Segment Information - Summary (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues		$ 187,251	$ 206,878	$ 578,658	$ 641,676
Property operating expenses		(56,296)	(60,912)	(174,949)	(190,807)
Interest expense		(50,515)	(55,194)	(156,995)	(163,164)
Other expense		(7)	(38)	(41)	(377)
Gain (loss) on sales of real estate assets		8,056	7,880	13,811	15,998
Segment profit (loss)		88,489	98,614	260,484	303,326
Depreciation and amortization expense		(64,168)	(71,945)	(198,438)	(217,261)
Interest and other income		1,367	283	2,212	714
Gain on extinguishment of debt		0	0	71,722	0
Loss on impairment		(135,688)	(14,600)	(202,121)	(84,644)
Net loss		(92,034)	(2,971)	(168,531)	(33,608)
Capital expenditures		36,491	41,183	97,603	115,656
Total Assets	[1]	4,769,918		4,769,918		$ 5,340,853
Malls
Segment Reporting Information [Line Items]
Revenues		171,514	188,440	526,354	585,097
Property operating expenses		(53,384)	(57,243)	(164,164)	(179,012)
Interest expense		(20,866)	(24,665)	(65,612)	(76,401)
Other expense		0	0	0	(84)
Gain (loss) on sales of real estate assets		3,292	92	5,770	92
Segment profit (loss)		100,556	106,624	302,348	329,692
Capital expenditures		34,961	38,512	94,545	105,593
Total Assets		4,351,303		4,351,303		4,868,141
All Other
Segment Reporting Information [Line Items]
Revenues		15,737	18,438	52,304	56,579
Property operating expenses		(2,912)	(3,669)	(10,785)	(11,795)
Interest expense		(29,649)	(30,529)	(91,383)	(86,763)
Other expense		(7)	(38)	(41)	(293)
Gain (loss) on sales of real estate assets		4,764	7,788	8,041	15,906
Segment profit (loss)		(12,067)	(8,010)	(41,864)	(26,366)
Capital expenditures		1,530	2,671	3,058	10,063
Total Assets		418,615		418,615		472,712
Guarantor Subsidiaries
Segment Reporting Information [Line Items]
Revenues		69,328	78,655	211,187	237,684
Property operating expenses		(21,241)	(23,501)	(64,427)	(70,444)
Interest expense		(3,400)	(6,129)	(10,797)	(18,270)
Other expense		(12)	(5)	(639)	(40)
Gain (loss) on sales of real estate assets		20	698	20	2,406
Segment profit (loss)		44,695	49,718	135,344	151,336
Depreciation and amortization expense		(24,681)	(24,481)	(71,499)	(73,587)
Interest and other income		1,022	1,857	3,049	6,077
Gain on extinguishment of debt		0	0	61,796	0
Loss on impairment		0	0	(22,770)	0
Net loss		21,036	27,094	105,920	83,826
Capital expenditures		11,096	10,394	29,648	30,675
Total Assets		1,692,703		1,692,703		1,841,860
Guarantor Subsidiaries | Malls
Segment Reporting Information [Line Items]
Revenues		66,708	76,009	203,511	229,576
Property operating expenses		(20,785)	(22,841)	(62,794)	(68,513)
Interest expense		(3,400)	(6,129)	(10,797)	(18,270)
Other expense		(10)	(5)	(637)	(40)
Gain (loss) on sales of real estate assets		20	698	20	2,406
Segment profit (loss)		42,533	47,732	129,303	145,159
Capital expenditures		10,692	10,391	29,221	30,308
Total Assets		1,566,677		1,566,677		1,697,211
Guarantor Subsidiaries | All Other
Segment Reporting Information [Line Items]
Revenues		2,620	2,646	7,676	8,108
Property operating expenses		(456)	(660)	(1,633)	(1,931)
Interest expense		0	0	0	0
Other expense		(2)	0	(2)	0
Gain (loss) on sales of real estate assets		0	0	0	0
Segment profit (loss)		2,162	1,986	6,041	6,177
Capital expenditures		404	$ 3	427	$ 367
Total Assets		$ 126,026		$ 126,026		$ 144,649

[1] As of September 30, 2019, includes $484,345 of assets related to consolidated variable interest entities that can be used only to settle obligations of the consolidated variable interest entities and $346,999 of liabilities of consolidated variable interest entities for which creditors do not have recourse to the general credit of the Company. See Note 7.