Combined Guarantor Subsidiaries - Fair Value Measurements - Impairment of Real Estate Properties (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		$ 239,521,000	$ 174,529,000	$ 71,401,000
Long-lived assets	$ 199,740,000	199,740,000	91,841,000	81,350,000
Greenbrier Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		22,770,000
Long-lived assets	56,300,000	56,300,000
Park Plaza Mall
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment	37,400,000
Park Plaza Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		37,400,000
Long-lived assets	$ 39,000,000	$ 39,000,000
Park Plaza Mall \| Malls \| Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Holding period	10 years
Park Plaza Mall \| Malls \| Cap Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	0.130	0.130
Park Plaza Mall \| Malls \| Discount Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	0.140	0.140
Acadiana Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets			3,920,000	$ 67,300,000	$ 67,300,000
Acadiana Mall \| Malls \| Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Holding period				10 years
Acadiana Mall \| Malls \| Cap Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)				0.155
Acadiana Mall \| Malls \| Discount Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)				0.1575
Guarantor Subsidiaries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		$ 60,170,000	$ 0	$ 43,007,000
Long-lived assets	$ 95,300,000	95,300,000		67,300,000
Guarantor Subsidiaries \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		60,170,000
Long-lived assets	95,300,000	95,300,000
Guarantor Subsidiaries \| Greenbrier Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		22,770,000
Long-lived assets	$ 56,300,000	$ 56,300,000
Guarantor Subsidiaries \| Greenbrier Mall \| Malls \| Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Holding period		10 years
Guarantor Subsidiaries \| Greenbrier Mall \| Malls \| Cap Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	11.0	11.0
Guarantor Subsidiaries \| Greenbrier Mall \| Malls \| Discount Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	11.5	11.5
Guarantor Subsidiaries \| Park Plaza Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment		$ 37,400,000
Long-lived assets	$ 39,000,000	$ 39,000,000
Guarantor Subsidiaries \| Park Plaza Mall \| Malls \| Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Holding period		10 years
Guarantor Subsidiaries \| Park Plaza Mall \| Malls \| Cap Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	15.0	15.0
Guarantor Subsidiaries \| Park Plaza Mall \| Malls \| Discount Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)	14.0	14.0
Guarantor Subsidiaries \| Acadiana Mall \| Malls
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss on impairment				43,007,000
Long-lived assets				$ 67,300,000
Guarantor Subsidiaries \| Acadiana Mall \| Malls \| Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Holding period				10 years
Guarantor Subsidiaries \| Acadiana Mall \| Malls \| Cap Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)				15.5
Guarantor Subsidiaries \| Acadiana Mall \| Malls \| Discount Rate (as a percent)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement input (as a percent)				15.75