Mortgages, construction loan payable and credit line (Schedule of Principal Amounts Due) (Details) $ in Thousands	Oct. 31, 2017 USD ($)
Debt Disclosure [Abstract]
2018	$ 125,065	[1]
2019	72,082
2020	3,575
2021	22,288
2022	$ 20,291

[1] Includes approximately $115.3 million relating to the Rotunda construction loan due February 2018. (See Note 4(M) to FREIT's consolidated financial statements.)