Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
May 31, 2014	May 31, 2014
Consolidated Statements of Operations
Loss from sale of assets net of tax	$ 31	$ 28

Represents the amount of loss from sale of assets net of tax.

No definition available.

Name:	grif_DiscontinuedOperationLossFromSaleOfAssetsNetOfTax
Namespace Prefix:	grif_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration