Commitments and Contingencies (Details) (Power Control Systems [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Jul. 01, 2007	Sep. 25, 2011
Power Control Systems [Member]
Divested entities tax obligations [Abstract]
Provision recorded for certain tax obligations with respect to divested entities	$ 18.6
Balance of the divested entities tax obligations		$ 3.8

Amount of deferred tax liability recognized pertaining to the parent company's indemnification liability of a disposed subsidiary that is a component of the entity (discontinued operation).

No definition available.

Name:	irf_BalanceOfDivestedEntitiesTaxObligations
Namespace Prefix:	irf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant