Financing Activity - Bridge Facility (Details)		9 Months Ended
	Oct. 16, 2020 USD ($)	Sep. 30, 2020 USD ($) Property
Bridge Facility
Debt Instrument [Line Items]
Number of properties | Property		12
Number of malls | Property		9
Number of additional parcels | Property		3
Debt instrument, maturity date		Oct. 31, 2020
Unused commitments fee percentage		0.50%
Percentage of actual aggregate disbursements not to exceed aggregate amount of disbursements during any four week testing period		20.00%
Debt instrument, payment terms		7 years
Minimum liquidity comprised of unrestricted cash held in certain deposit accounts subject to control agreements		$ 8,500,000
Maximum certain other deposit account not subject to control agreement		5,000,000.0
Maximum cash not retain in property level accounts held by subsidiaries		$ 6,500,000
Debt Instrument, restrictive covenants		The Bridge Facility contains, among other restrictions, certain affirmative and negative covenants, including, without limitation, requirements that the Borrower and certain of its subsidiaries (i) comply with all of the affirmative and negative covenants set forth in the 2018 Credit Agreement, (ii) promptly notify the administrative agent of any acquisition of any owned real property that is not subject to a mortgage and grant liens on such real property to secure the Bridge Facility, (iii) use the proceeds of the Bridge Facility for purposes consistent with certain categories set forth in the loan budget, (iv) provide weekly reports with respect to variances in actual results relative to projected amounts set forth in the loan budget and providing an explanation for any such deviation, certifying that no Default or Event of Default has occurred (or if one has occurred, specifying the nature and extent thereof and any corrective action taken or proposed to be taken with respect thereto), and beginning on the fourth week following the effective date certifying compliance with covenants limiting the permitted variation of certain actual disbursements by the Company and its subsidiaries from amounts set forth in the loan budget; (v) beginning with the fourth full week following the effective date, and for each rolling four-week period thereafter, the Borrower is required to cause certain of its actual aggregate disbursements not to exceed the aggregate amount of such disbursements in the loan budget by more than 20% during any such four-week testing period, (vi) prior to August 31, 2020, agree to a non-binding term sheet with respect to amendments of each of the 2018 Credit Agreement and the 7-Year Term Loan (which the Borrower satisfied on August 30, 2020), (vii) provide operating statements, rent rolls, collections and leasing information, as well as certain reports and agreements as the administrative agent may reasonably require, to the administrative agent for each of the Mortgaged Properties, (viii) maintain liquidity of at least $8.5 million, to be comprised of unrestricted cash held in certain deposit accounts subject to control agreements as well as up to $5.0 million held in a certain other deposit account not subject to a control agreement and the unused commitments under the Bridge Facility (to the extent available to be drawn); and (ix) not retain more than $6.5 million of cash in property-level accounts held by subsidiaries that are owners of real property (subject to certain exceptions).
Prepayment percentage of net cash proceeds from certain capital events		100.00%
Bridge Facility | Maximum
Debt Instrument [Line Items]
Unrestricted cash liquidity		$ 12,500,000
Bridge Facility | Credit Agreements
Debt Instrument [Line Items]
Debt instrument, maturity date		Oct. 31, 2020
Bridge Facility | Credit Agreements | Subsequent Event
Debt Instrument [Line Items]
Increase in aggregate amount of commitments	$ 25,000,000.0
Proceeds from line of credit	$ 25,000.0
Bridge Facility Base Rate Loans
Debt Instrument [Line Items]
Debt instrument interest rate		7.00%
Bridge Facility Base Rate Loans | Federal Funds Rate
Debt Instrument [Line Items]
Debt, variable interest rate		0.50%
Bridge Facility Base Rate Loans | LIBOR Market Index Rate
Debt Instrument [Line Items]
Debt, variable interest rate		1.00%
Bridge Facility Base Rate Loans | Base Rate | Minimum
Debt Instrument [Line Items]
Debt, variable interest rate		2.00%
Bridge Facility LIBOR Loans | LIBOR
Debt Instrument [Line Items]
Debt, variable interest rate		8.00%