Short-Term Financing (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2015
Short-term Debt [Line Items]
Long-term Line of Credit	$ 0.0		$ 0.0
Commercial Paper	$ 0.0		$ 0.0		$ 0.0
Maturities of commercial paper range			overnight to up to 364 days
Commercial Paper Weight Average Maturity	1 day
Maturities of short-term funding agreements			overnight to up to five business days
Obligations under reverse repurchase agreements	$ 0.0		$ 0.0		$ 0.0
Short Term Commercial Paper Program [Member]
Short-term Debt [Line Items]
Commercial Paper Weight Average Maturity	2 days
364-Day Credit Agreement [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 2,750.0		$ 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		$ 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		$ 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]
Aggregate amount of commercial paper issuable under the short-term commercial paper program	8,250.0
Short-term Debt, Average Outstanding Amount	$ 1,300.0	$ 1,000.0	$ 2,700.0	$ 2,400.0
Debt Instrument, Interest Rate During Period	0.40%	0.10%	0.20%	0.10%
Reverse Repurchase Agreements [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,250.0		$ 3,250.0
Short-term Debt, Average Outstanding Amount	$ 128.0	$ 93.0	$ 316.9	$ 423.2
Debt Instrument, Interest Rate During Period	0.50%	0.70%	0.40%	0.50%