Subsequent events (Details) (Subsequent Event [Member], USD $)	Feb. 17, 2015
Subsequent Event [Member]
Subsequent Event [Line Items]
Number Of Shares In Tender Offer	100,000
Price Per Share Of Tender Offer	$ 23.00
Percentage Of Outstanding Shares In Tender Offer	1.50%

Percentage of outstanding shares of the company that would be outstanding in a tender offer.

No definition available.

Name:	frevsob_PercentageOfOutstandingSharesInTenderOffer
Namespace Prefix:	frevsob_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant