Financing Activity - Credit Agreements (Details)					3 Months Ended	9 Months Ended
	Sep. 27, 2023 USD ($)	Oct. 01, 2021	Jun. 30, 2021	Dec. 10, 2020 USD ($)	Sep. 30, 2021	Sep. 30, 2023 USD ($) ft² Property	Sep. 30, 2022 USD ($)	Aug. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Outstanding line of credit						$ 99,406,000			$ 22,481,000
Amounts equal to greater than termination or modification of lease						2,500,000
Cash proceeds from sales of real estate						29,713,000	$ 39,515,000
Maximum
Debt Instrument [Line Items]
Amounts received on behalf of guarantor in consideration of termination or modification of lease.						$ 3,500,000
Minimum
Debt Instrument [Line Items]
Leased premises | ft²						7,500
Debt instrument discounted amount						$ 750,000
Percentage of aggregate contractual base rent						25.00%
Outstanding obligations						$ 3,500,000
Unsecured Debt
Debt Instrument [Line Items]
Debt issuance costs, line of credit arrangements						$ 500,000
First Lien Credit Agreement Base Rate Loans | Federal Funds Rate
Debt Instrument [Line Items]
Debt, variable interest rate						0.50%
First Lien Credit Agreement Base Rate Loans | LIBOR Market Index Rate
Debt Instrument [Line Items]
Debt, variable interest rate						1.00%
First Lien Credit Agreement Base Rate Loans | Base Rate
Debt Instrument [Line Items]
Debt, variable interest rate						1.50%
Second Lien Credit Agreement Base Rate Loan | Federal Funds Rate
Debt Instrument [Line Items]
Debt, variable interest rate							0.50%
Second Lien Credit Agreement Base Rate Loan | LIBOR Market Index Rate
Debt Instrument [Line Items]
Debt, variable interest rate						1.00%
Second Lien Credit Agreement Base Rate Loan | Base Rate
Debt Instrument [Line Items]
Debt, variable interest rate						1.50%
Debt instrument interest rate						7.00%
Second Lien Credit Agreement LIBOR Loans | Maximum
Debt Instrument [Line Items]
Debt, variable interest rate						0.50%
Second Lien Credit Agreement LIBOR Loans | LIBOR
Debt Instrument [Line Items]
Debt, variable interest rate						8.00%
Credit Agreements
Debt Instrument [Line Items]
Debt instrument maturity period				2022-12		2023-12
Number of properties | Property						10
Number of malls | Property						9
Number of additional parcels | Property						1
Percentage of minimum corporate debt yield		7.25%			6.50%
Debt Instrument, restrictive covenants						In December 2022, we exercised our option and satisfied the conditions to extend the maturity date of our Credit Agreements, such that it is now December 10, 2023 (the “Maturity Date”). See Going Concern Considerations section in Note 1. The loans under the Credit Agreements are repayable in full on the Maturity Date, subject to mandatory prepayment provisions in the event of certain events including asset sales, incurrence of indebtedness, issuances of equity and receipt of casualty insurance proceeds. The terms of our Credit Agreements place restrictions on, among other things, and subject to certain exceptions, our ability to make certain restricted payments (including payments of dividends), make certain types of investments and acquisitions, issue redeemable securities, incur additional indebtedness, incur liens on our assets, enter into agreements with a negative pledge, make certain intercompany transfers, merge, consolidate, or sell our assets or the equity interests in our subsidiaries, amend our organizational documents or material contracts, enter into certain transactions with affiliates, or enter into derivatives contracts. Additionally, if we receive net cash proceeds from certain capital events (including equity issuances), we are required to prepay loans under our Credit Agreements. In addition, the Credit Agreements contain cross-default provisions that trigger an event of default if we fail to make certain payments or otherwise fail to comply with our obligations with respect to certain of our other indebtedness.
Minimum liquidity comprised of unrestricted cash held in certain deposit accounts subject to control agreements						$ 25,000,000
Maximum certain other deposit account not subject to control agreement						5,000,000
Percentage of minimum senior debt yield			11.35%
Maximum cash not retain in property level accounts held by subsidiaries						$ 6,500,000
Debt instrument, maturity date						Dec. 10, 2023
Credit Agreements | SOFR
Debt Instrument [Line Items]
Debt, variable interest rate						0.10%
Credit Agreements | First Lien Term Loan
Debt Instrument [Line Items]
Outstanding borrowings						$ 305,700,000		$ 15,000,000
Credit Agreements | Second Lien Term Loan
Debt Instrument [Line Items]
Outstanding borrowings						713,700,000
Credit Agreements | First Lien Revolving Facility
Debt Instrument [Line Items]
Outstanding borrowings	$ 2,900,000					99,400,000
Additional amount borrowed						56,900,000
Outstanding line of credit						99,400,000
Remaining borrowing capacity						$ 30,600,000
Credit Agreements | First Lien Revolving Facility | Dartmouth Mall Mortgage
Debt Instrument [Line Items]
Outstanding borrowings	54,000
Credit Agreements | First Lien Revolving Facility | Maximum | Dartmouth Mall Mortgage
Debt Instrument [Line Items]
Cash proceeds from sales of real estate	$ 54,000,000
Secured First Lien Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing				$ 130,000,000
Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing				10,000,000
First Lien Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing				384,500,000
Second Lien Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing				$ 535,200,000
Revolving Loans
Debt Instrument [Line Items]
Debt, variable interest rate						2.50%
Revolving Loans | LIBOR
Debt Instrument [Line Items]
Debt, variable interest rate						3.50%
First Lien Credit Agreement
Debt Instrument [Line Items]
Days of interest period						30 days
Percentage of amount greater than equal to 50% of aggregate amount of revolving commitments						0.35%
Percentage of daily amount of unused revolving commitments						50.00%
Percentage of amount less than 50% of aggregate amount of revolving commitments						0.25%
Debt instrument, variable rate description						Amounts borrowed under the First Lien Credit Agreement may be either Base Rate Loans or LIBOR Loans. Base Rate Loans bear interest at the highest of (a) the Prime Rate, (b) the Federal Funds Rate plus 0.50% and (c) the LIBOR Market Index Rate plus 1.0%, provided that the Base Rate will not be less than 1.50% per annum, in each case plus (w) for revolving loans, 2.50% per annum, and (x) for term loans, 4.74% per annum. LIBOR Loans bear interest at LIBOR plus (y) for revolving loans, 3.50% per annum, and (z) for term loans, 5.74% per annum, in each case, provided that LIBOR will not be less than 0.50% per annum. Interest is due to be paid in cash on the last day of each applicable interest period (with rolling 30-day interest periods) and on the Maturity Date. We are required to pay certain fees to the administrative agent
First Lien Credit Agreement | LIBOR | Maximum
Debt Instrument [Line Items]
Debt, variable interest rate						0.50%
First Lien Credit Agreement | Term Loans
Debt Instrument [Line Items]
Debt, variable interest rate						4.74%
First Lien Credit Agreement | Term Loans | LIBOR
Debt Instrument [Line Items]
Debt, variable interest rate						5.74%
Second Lien Credit Agreement
Debt Instrument [Line Items]
Days of interest period						30 days
Debt instrument, variable rate description						Amounts borrowed under the Second Lien Credit Agreement may be either Base Rate Loans or LIBOR Loans. Base Rate Loans bear interest at the highest of (a) the Prime Rate, (b) the Federal Funds Rate plus 0.50% and (c) the LIBOR Market Index Rate plus 1.0%, provided that the Base Rate will not be less than 1.50% per annum, in each case plus 7.00% per annum. LIBOR Loans bear interest at LIBOR plus 8.00% per annum, provided that LIBOR will not be less than 0.50% per annum. Interest is due to be paid in kind on the last day of each applicable interest period (with rolling 30-day interest periods) by adding the accrued and unpaid amount thereof to the principal balance of the loans under the Second Lien Credit Agreement and then accruing interest on the increased principal amount (provided that after the discharge of our obligations under the First Lien Credit Agreement and any other senior debt obligations, interest will be paid in cash). We are required to pay certain fees to the administrative agent for the account of the lenders in connection with the Second Lien Credit Agreement.