Statements of Consolidated Earnings (Unaudited) Parenthetical - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Direct Pass Through Costs P E O Revenues	$ 9,207.2	$ 8,374.8	$ 26,040.3	$ 23,613.0

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