Combined Guarantor Subsidiaries - Fair Value Measurements - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) mall	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term debt	$ 3,479,729		$ 3,479,729		$ 3,740,431
Loss on impairment	41,608	$ 51,983	$ 66,433	$ 70,044
Number of malls with impairment | mall			3
Guarantor Subsidiaries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term debt	256,285		$ 256,285		$ 319,222
Loss on impairment	$ 0	$ 0	$ 22,770	$ 0
Number of malls with impairment | mall			1