Commitments And Contingencies Commitment and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Commitments And Contingencies [Abstract]
Incremental increase in Purchase Obligation due within four years	$ 64.5
Incremental increase in Purchase Obligation due within Five years	$ 43.5

Incremental Increase in Purchase Obligation due within Five years

No definition available.

Name:	adp_IncrementalIncreaseinPurchaseObligationduewithinFiveyears
Namespace Prefix:	adp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant