Interest rate cap and swap contracts (Details) - USD ($)			1 Months Ended		12 Months Ended
	Feb. 07, 2018	Dec. 07, 2017	Feb. 28, 2020	Sep. 29, 2016	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018	Apr. 22, 2016	Dec. 26, 2012
Derivative [Line Items]
Unrealized gain (loss) on derivatives						$ (160,000)	$ 72,000
Net unrealized (loss) gain on interest rate swap contracts					(2,798,000)	(6,400,000)	3,113,000
Interest rate swap contract liabilities					4,924,000	2,126,000
Damascus Centre Swap [Member]
Derivative [Line Items]
Interest rate swap contract assets							955,000
Interest rate swap contract liabilities					610,000	179,000
Wayne PSC swap [Member]
Derivative [Line Items]
Interest rate swap contract assets							2,452,000
Interest rate swap contract liabilities					1,260,000	53,000
Regency Swap [Member]
Derivative [Line Items]
Interest rate swap contract assets							408,000
Interest rate swap contract liabilities					1,385,000	860,000
Station Place swap [Member]
Derivative [Line Items]
Interest rate swap contract assets							460,000
Interest rate swap contract liabilities					1,669,000	1,034,000
Grande Rotunda interest rate cap [Member]
Derivative [Line Items]
Interest rate swap contract liabilities					0	$ 0
Station Place [Member]
Derivative [Line Items]
Percentage of acquisition		100.00%
Loan amount		$ 12,350,000
Notional amount of interest rate swap					12,200,000
Fixed interest rate		4.35%
Basis points, interest rate		1.80%
Maturity date of loan		Dec. 15, 2027
Aareal Capital Corporation [Member]
Derivative [Line Items]
Loan amount	$ 118,500,000
Available to draw	$ 3,380,000
Basis points, interest rate	2.85%
Maturity date of loan	Feb. 06, 2021
Grande Rotunda LLC Loan [Member]
Derivative [Line Items]
Derivative notional amount					$ 121,900,000
Maturity date of cap					Mar. 05, 2021
Grande Rotunda LLC Loan [Member] | Two Years [Member]
Derivative [Line Items]
Loan amount					$ 118,500,000
Notional amount of interest rate swap					$ 121,900,000
Interest rate cap					3.00%
Maturity date of cap					Mar. 05, 2020
Grande Rotunda LLC Loan [Member] | One Years [Member]
Derivative [Line Items]
Notional amount of interest rate swap			$ 121,900,000
Interest rate cap			3.00%
Maturity date of cap			Mar. 05, 2020
Wayne PSC Loan [Member]
Derivative [Line Items]
Refinanced loan amount				$ 24,200,000
Loan amount				$ 25,800,000	$ 23,300,000
Notional amount of interest rate swap					23,100,000
Fixed interest rate				3.625%
Basis points, interest rate				2.20%
Maturity date of loan				Oct. 01, 2026
People's United Bank [Member]
Derivative [Line Items]
Loan amount					18,800,000
Notional amount of interest rate swap					$ 18,900,000
People's United Bank [Member] | Tranche One [Member]
Derivative [Line Items]
Loan amount									$ 20,000,000
Fixed interest rate					3.81%
Basis points, interest rate					2.10%
Maturity date of loan					Jan. 03, 2023
People's United Bank [Member] | Tranche Two [Member]
Derivative [Line Items]
Loan amount								$ 2,320,000
Fixed interest rate					3.53%
Regency Loan [Member]
Derivative [Line Items]
Refinanced loan amount					$ 16,200,000
Loan amount					15,300,000
Notional amount of interest rate swap					$ 15,300,000
Basis points, interest rate					1.25%
Maturity date of loan					Dec. 15, 2024
Grande Rotunda LLC [Member]
Derivative [Line Items]
Unrealized gain (loss) on derivatives							72,000
Interest rate cap asset							$ 160,000