Interest rate cap and swap contracts (Details) - USD ($)		1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 10, 2022	Dec. 30, 2021	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2021	Oct. 31, 2021
Derivative [Line Items]
Interest rate swap contract liability							$ 2,308,000
Net unrealized gain (loss) on interest rate swap contracts			2,539,000	$ 1,177,000	3,801,000	$ 1,675,000
Regency Swap [Member]
Derivative [Line Items]
Interest rate swap contract liability			131,000		131,000		750,000
Grande Rotunda [Member]
Derivative [Line Items]
Interest rate swap contract liability							0
Station Place [Member]
Derivative [Line Items]
Interest rate swap contract liability			158,000		158,000		932,000
Damascus Centre Swap [Member]
Derivative [Line Items]
Interest rate swap contract liability							278,000
Wayne PSC swap [Member]
Derivative [Line Items]
Interest rate swap contract asset			$ 1,204,000		$ 1,204,000
Interest rate swap contract liability							$ 348,000
Purchase and Sale Agreement of Damascus Property [Member]
Derivative [Line Items]
Repayments of mortgage debt	$ 18,200,000
Purchase and Sale Agreement of Maryland Properties [Member]
Derivative [Line Items]
Repayments of mortgage debt	155,800,000
Swap breakage fees	$ 213,000
Purchase and Sale Agreement of Rotunda Property [Member]
Derivative [Line Items]
Repayments of mortgage debt		$ 116,500,000