Short-Term Financing (Details) - USD ($)	12 Months Ended
	Jun. 30, 2019		Jun. 30, 2018
Short-term Debt [Line Items]
Credit borrowings	$ 0		$ 0
Commercial Paper	$ 0		0
Maturities of short-term funding agreements	overnight to up to five business days
Obligations under reverse repurchase agreements	$ 262,000,000	[1]	$ 0
364-Day Credit Agreement [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,800,000,000
Term of credit	364 days
Expiration date of credit facilities	Jun. 30, 2020
Debt Instrument, Extension Option Term	1 year
Credit Facility Expiring In June Two Thousand Twenty Four [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 2,750,000,000
Term of credit	5 years
Expiration date of credit facilities	Jun. 30, 2024
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500,000,000
Short-Term Commercial Paper Program [Member]
Short-term Debt [Line Items]
Weighted average maturity of borrowings under the short-term commercial paper program	2 days		2 days
Reverse Repurchase Agreements [Member]
Short-term Debt [Line Items]
Short-term Debt, Average Outstanding Amount	$ 316,700,000		$ 374,400,000
Debt Instrument, Interest Rate During Period	1.90%		1.30%
Credit Facility Expiring In June Two Thousand Twenty One [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,750,000,000
Term of credit	5 years
Expiration date of credit facilities	Jun. 30, 2023
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500,000,000
Commercial Paper [Member]
Short-term Debt [Line Items]
Aggregate amount of commercial paper issuable under the short-term commercial paper program	$ 10,300,000,000		$ 9,800,000,000
Maturities of commercial paper range	overnight to up to 364 days
Short-term Debt, Average Outstanding Amount	$ 2,800,000,000		$ 2,800,000,000
Debt Instrument, Interest Rate During Period	2.20%		1.40%

[1] (A) As of June 30, 2019, $261.4 million of long-term marketable securities and $0.6 million of cash and cash equivalents have been pledged as collateral under the Company's reverse repurchase agreements (see Note 10).