Statements of Consolidated Earnings (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Direct pass-through costs PEO revenues	$ 81,123.2	$ 75,220.1	$ 69,874.1

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