Statements of Consolidated Earnings (Unaudited) Parenthetical - USD ($) $ in Millions	3 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Direct pass through costs P E O revenues	$ 8,738.5	$ 7,687.6

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