Interest rate cap and swap contracts (Details) - USD ($)	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020	Oct. 31, 2020
Derivative [Line Items]
Interest rate swap contract liability	$ 3,249,000		$ 3,249,000		$ 4,924,000
Net unrealized gain (loss) on interest rate swap contracts	1,177,000	$ (2,982,000)	1,675,000	$ (3,372,000)
Damascus Centre Swap [Member]
Derivative [Line Items]
Interest rate swap contract liability	459,000		459,000		610,000
Wayne PSC swap [Member]
Derivative [Line Items]
Interest rate swap contract liability	616,000		616,000		1,260,000
Regency Swap [Member]
Derivative [Line Items]
Interest rate swap contract liability	1,068,000		1,068,000		1,385,000
Station Place [Member]
Derivative [Line Items]
Interest rate swap contract liability	1,106,000		1,106,000		1,669,000
Grande Rotunda LLC [Member]
Derivative [Line Items]
Interest rate swap contract liability	$ 0		$ 0		$ 0