Short-Term Financing (Details) - USD ($)	12 Months Ended
	Jun. 30, 2020		Jun. 30, 2019
Short-term Debt [Line Items]
Credit borrowings	$ 1,001,800,000		$ 0
Commercial Paper	$ 0
Maturities of short-term funding agreements	overnight to up to five business days
Obligations under reverse repurchase agreements	$ 13,600,000	[1]	262,000,000.0
Line of Credit Facility, Fair Value of Amount Outstanding	0
364-Day Credit Agreement [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 3,200,000,000
Term of credit	364 days
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
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500,000,000
Reverse Repurchase Agreements [Member]
Short-term Debt [Line Items]
Short-term Debt, Average Outstanding Amount	$ 263,400,000		$ 316,700,000
Debt Instrument, Interest Rate During Period	1.60%		1.90%
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
Line of credit facility potentially available increase in maximum borrowing capacity	$ 500,000,000
Commercial Paper [Member]
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities	$ 9,700,000,000		$ 10,300,000,000
Maturities of commercial paper range	overnight to up to 364 days
Weighted average maturity of borrowings under the short-term commercial paper program	2 days		2 days
Short-term Debt, Average Outstanding Amount	$ 2,700,000,000		$ 2,800,000,000
Debt Instrument, Interest Rate During Period	1.60%		2.20%

[1] (A) As of June 30, 2020, $13.6 million of long-term marketable securities have been pledged as collateral under the Company's reverse repurchase agreements. 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 8).