Investment in tenancy-in-common (Schedule of balance sheet of Pierre Property) (Details) - USD ($) $ in Thousands	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018
Schedule of Equity Method Investments [Line Items]
Real estate, net	$ 287,536			$ 330,108
Cash and cash equivalents	31,034			38,075	$ 26,068
Tenants' security accounts	1,590			2,278
Receivables and other assets	2,130			1,741
Total Assets	361,104			390,618
Mortgages payable, net of unamortized debt issuance costs	300,692			349,904
Accounts payable and accrued expenses	2,475			3,097
Tenants' security deposits	2,229			3,381
Deferred revenue	728			1,390
Equity	40,701	$ 41,205	$ 13,277	16,048	$ 18,095	$ 20,448	$ 21,369	$ 24,344
Total Liabilities and Equity	361,104			390,618
FREIT's investment in TIC (65% interest)	20,662
Pierre Property [Member]
Schedule of Equity Method Investments [Line Items]
Real estate, net	80,558
Cash and cash equivalents	1,557
Tenants' security accounts	569
Receivables and other assets	483
Total Assets	83,167
Mortgages payable, net of unamortized debt issuance costs	50,022
Accounts payable and accrued expenses	725
Tenants' security deposits	562
Deferred revenue	71
Equity	31,787
Total Liabilities and Equity	83,167
FREIT's investment in TIC (65% interest)	$ 20,662