Financial Data By Segment (Financial Data By Strategic Business Unit Segment) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenues	$ 2,573.8	$ 2,362.0
Earnings from Continuing Operations before Income Taxes	452.5	403.6
Employer Services [Member]
Segment Reporting Information [Line Items]
Revenues	2,099.1	1,963.2
Earnings from Continuing Operations before Income Taxes	584.2	523.3
PEO Services [Member]
Segment Reporting Information [Line Items]
Revenues	594.9	505.1
Earnings from Continuing Operations before Income Taxes	66.7	51.9
Other Segments [Member]
Segment Reporting Information [Line Items]
Revenues	(0.1)	0.1
Earnings from Continuing Operations before Income Taxes	(78.3)	(65.2)
Client Fund Interest [Member]
Segment Reporting Information [Line Items]
Revenues	(120.1)	(106.4)
Earnings from Continuing Operations before Income Taxes	$ (120.1)	$ (106.4)