Statements Of Consolidated Earnings (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Statements Of Consolidated Earnings
Provision for income taxes discontinued operations			$ 7.0
Direct pass-through costs, Professional Employer Organization revenues	$ 17,792.2	$ 15,765.3	$ 13,318.7

Direct pass-through costs associated with PEO, primarily consisting of payroll wages and payroll taxes.

No definition available.

Name:	adp_DirectPassThroughCostsPEORevenues
Namespace Prefix:	adp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration