Combined Guarantor Subsidiaries - Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Rental revenues		$ 200,311		$ 620,608
Total revenues	$ 187,251	206,878	$ 578,658	641,676
Malls
Disaggregation of Revenue [Line Items]
Total revenues	171,514	188,440	526,354	585,097
All Other
Disaggregation of Revenue [Line Items]
Total revenues	15,737	18,438	52,304	56,579
Total Revenue
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	5,721	5,906	17,126	18,004
Operating expense reimbursements
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	2,449	2,086	6,653	6,597
Marketing revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	1,056	1,162	3,148	3,385
Marketing revenues | Malls
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	2,374	1,903	6,458	6,176
Marketing revenues | All Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	75	183	195	421
Other revenues
Disaggregation of Revenue [Line Items]
Other revenues	914	661	4,543	3,064
Guarantor Subsidiaries
Disaggregation of Revenue [Line Items]
Rental revenues	67,495	77,067	206,083	232,749
Total revenues	69,328	78,655	211,187	237,684
Guarantor Subsidiaries | Malls
Disaggregation of Revenue [Line Items]
Total revenues	66,708	76,009	203,511	229,576
Guarantor Subsidiaries | All Other
Disaggregation of Revenue [Line Items]
Total revenues	2,620	2,646	7,676	8,108
Guarantor Subsidiaries | Total Revenue
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	1,779	1,469	4,609	4,520
Guarantor Subsidiaries | Operating expense reimbursements
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	1,217	910	3,061	3,044
Guarantor Subsidiaries | Operating expense reimbursements | Malls
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	1,232	903	3,072	3,020
Guarantor Subsidiaries | Operating expense reimbursements | All Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	(15)	7	(11)	24
Guarantor Subsidiaries | Marketing revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers (ASC 606):	562	559	1,548	1,476
Guarantor Subsidiaries | Other revenues
Disaggregation of Revenue [Line Items]
Other revenues	$ 54	$ 119	$ 495	$ 415