Short-Term Financing (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015
Short-term Debt [Line Items]
Long-term Line of Credit	$ 0.0
Commercial Paper	$ 0.0		$ 0.0
Maturities of commercial paper range	overnight to up to 364 days
Commercial Paper Weight Average Maturity	2 days
Maturities of short-term funding agreements	overnight to up to five business days
Obligations under reverse repurchase agreements	$ 0.0		$ 0.0
364-Day Credit Agreement [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 2,750.0
Term of credit	364 days
Expiration date of credit facilities	Jun. 16, 2016
Credit Facility Expiring In June Two Thousand Nineteen [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,250.0
Term of credit	5 years
Expiration date of credit facilities	Jun. 18, 2019
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500.0
Credit Facility Expiring In June Two Thousand Twenty [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 2,250.0
Term of credit	5 years
Expiration date of credit facilities	Jun. 17, 2020
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500.0
Commercial Paper [Member]
Short-term Debt [Line Items]
Debt Instrument, Unused Borrowing Capacity, Description	8250
Short-term Debt, Average Outstanding Amount	$ 3,500.0	$ 3,100.0
Debt Instrument, Interest Rate During Period	0.20%	0.10%
Reverse Repurchase Agreements [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,250.0
Short-term Debt, Average Outstanding Amount	$ 485.6	$ 570.7
Debt Instrument, Interest Rate During Period	0.40%	0.40%