Mortgage Loans Payable and Unsecured Credit Facility (Schedule of Debt and Finance Lease Obligations Related to Continuing Operations) (Parenthetical) (Details)		3 Months Ended
Aug. 04, 2020	Mar. 31, 2021
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility extension allowed period	1 year	1 year

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration