Income Taxes (Reconciliation of U.S. Federal Statutory Rate To Effective Tax Rate) (Details) - USD ($) $ in Millions		12 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Income Tax Disclosure [Abstract]
Provision for taxes at U.S. statutory rate		$ 724.8	$ 657.7	$ 598.4
Provision for taxes at U.S. statutory rate, percent		35.00%	35.00%	35.00%
State taxes, net of federal tax benefit		$ 34.8	$ 33.4	$ 25.9
State taxes, net of federal tax benefit, percent		1.70%	1.80%	1.50%
U.S. tax on foreign income		$ 155.3	$ 26.6	$ 85.2
U.S. tax on foreign income, percent		7.50%	1.40%	5.00%
Utilization of foreign tax credits		$ (177.1)	$ (26.2)	$ (95.1)
Utilization of foreign tax credits, percent		(8.60%)	(1.40%)	(5.50%)
Section 199 - Qualified production activities		$ (28.9)	$ (23.0)	$ (22.3)
Section 199 - Qualified production activities, percent		(1.40%)	(1.20%)	(1.30%)
Other	[1]	$ (14.7)	$ (31.9)	$ (4.2)
Other, percent	[1]	(0.70%)	(1.70%)	(0.30%)
Provision for income taxes from continuing operations		$ 694.2	$ 636.6	$ 587.9
Effective Income Tax Rate, Continuing Operations		33.50%	33.90%	34.40%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount			$ 16.0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Percent				0.80%

[1] Fiscal 2013 includes $16.0 million for the tax impact of the non tax-deductible goodwill impairment related to ADP AdvancedMD which increased our fiscal 2013 effective tax rate 0.8 percentage points.