Note 11 - Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Amount Financed by Dealers	$ 30,500gnrc_AmountFinancedByDealers	$ 26,100gnrc_AmountFinancedByDealers

Amount financed by dealers to purchase goods from the entity.

No definition available.

Name:	gnrc_AmountFinancedByDealers
Namespace Prefix:	gnrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant