Statements of Consolidated Earnings (Parenthetical) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Direct pass-through costs PEO revenues	$ 16,774.0	$ 13,349.1	$ 30,037.2	$ 24,364.9

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