Short-term Financing (Details) - USD ($)		3 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017
Short-term Debt [Line Items]
Short-term debt		$ 0
Commercial paper		$ 0		$ 0
Maturities of short-term funding agreements		overnight to up to five business days
Obligations under reverse repurchase agreements	[1]	$ 129,400,000		$ 0
364-day credit agreement
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		$ 3,500,000,000
Term of credit agreement		364 days
Expiration date of credit facilities		Jun. 16, 2018
Extension option term		1 year
Credit Facility Expiring In June 2022
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		$ 2,250,000,000
Term of credit agreement		5 years
Expiration date of credit facilities		Jun. 17, 2022
Line of credit facility potentially available increase in maximum borrowing capacity		$ 500,000,000
Credit facility maturing June 2021
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		$ 3,750,000,000
Term of credit agreement		5 years
Expiration date of credit facilities		Jun. 18, 2021
Line of credit facility potentially available increase in maximum borrowing capacity		$ 500,000,000
Commercial paper program
Short-term Debt [Line Items]
Aggregate amount of commercial paper issuable under the short-term commercial paper program		$ 9,500,000,000
Maturities of commercial paper range		overnight to up to 364 days
Short-term debt, average outstanding amount		$ 3,800,000,000	$ 4,100,000,000
Debt instrument, interest rate during period		1.20%	0.40%
Short Term Commercial Paper Program
Short-term Debt [Line Items]
Commercial paper weighted average maturity		2 days	2 days
Reverse repurchase agreements
Short-term Debt [Line Items]
Short-term debt, average outstanding amount		$ 526,200,000	$ 359,300,000
Debt instrument, interest rate during period		1.10%	0.60%

[1] (A) As of September 30, 2017, $110.0 million of short-term marketable securities, $19.3 million of long-term marketable securities and $0.1 million of cash and cash equivalents have been pledged as collateral under the Company's reverse repurchase agreements (see Note 8).