Statements of Consolidated Earnings (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Sep. 30, 2026	Sep. 30, 2025
Income Statement [Abstract]
Professional employer organization revenue, direct pass-through costs	$ 18,991.0	$ 18,534.4

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