Financial Data By Segment And Geographic Area (Financial Data By Strategic Business Unit Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 16,498.3	$ 15,005.4	$ 14,589.8
Earnings before income taxes	3,804.1	3,361.2	3,182.6
Capital expenditures	177.1	178.3	168.3
Depreciation and amortization	515.1	510.7	480.0
Other
Segment Reporting Information [Line Items]
Revenues	(15.1)	(8.1)	(8.3)
Earnings before income taxes	(473.4)	(409.7)	(484.9)
Capital expenditures	51.7	61.6	52.6
Depreciation and amortization	78.3	81.6	88.6
Employer Services | Operating Segments
Segment Reporting Information [Line Items]
Revenues	10,967.7	10,195.2	10,086.6
Earnings before income taxes	3,406.3	3,052.1	3,058.2
Capital expenditures	125.4	116.7	115.7
Depreciation and amortization	428.5	421.7	388.0
PEO Services | Operating Segments
Segment Reporting Information [Line Items]
Revenues	5,545.7	4,818.3	4,511.5
Earnings before income taxes	871.2	718.8	609.3
Capital expenditures	0.0	0.0	0.0
Depreciation and amortization	$ 8.3	$ 7.4	$ 3.4