Financing Arrangement - Narrative (Details) ft² in Thousands, $ in Thousands			12 Months Ended
	Jun. 27, 2019 USD ($)	Sep. 30, 2009 ft²	Dec. 31, 2019 USD ($) $ / ft²	Dec. 31, 2018 USD ($) $ / ft²	Dec. 31, 2017 USD ($)	Jan. 01, 2018 USD ($)
Distributions of the partner's share of net income
Financing arrangement obligation			$ 273,900	$ 378,485
Accumulated deficit			$ (1,944,012)	$ (1,614,357)
Terminal capitalization rate			5.00%	4.80%
Discount rate			6.00%	5.80%
Distributions in excess of loan proceeds	$ 27,945		$ 27,945	$ 0	$ 0
Freehold Raceway Mall and Chandler Fashion Center | Joint venture
Distributions of the partner's share of net income
Investments in unconsolidated joint ventures						$ 31,150
Chandler Fashion Center
Distributions of the partner's share of net income
Mortgage loan	$ 256,000
Financing arrangement | Minimum
Distributions of the partner's share of net income
Market rent per square foot			35	35
Financing arrangement | Maximum
Distributions of the partner's share of net income
Market rent per square foot | $ / ft²			115	115
Financing arrangement | ASU 2014-09 | Difference between revenue guidance in effect before and after topic 606 | Freehold Raceway Mall and Chandler Fashion Center | Joint venture
Distributions of the partner's share of net income
Financing arrangement obligation						393,709
Accumulated deficit						424,859
Financing arrangement | Freehold Raceway Mall and Chandler Fashion Center
Distributions of the partner's share of net income
Ownership interest (as a percent)		49.90%
Financing arrangement | Chandler Fashion Center
Distributions of the partner's share of net income
Property area (in square feet) | ft²		1,318
Financing arrangement | Freehold Raceway Mall
Distributions of the partner's share of net income
Property area (in square feet) | ft²		1,673
Joint venture | Freehold Raceway Mall and Chandler Fashion Center
Distributions of the partner's share of net income
Investments in unconsolidated joint ventures						$ 31,150