Short-term Financing (Details) - USD ($)		3 Months Ended		6 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Short-term Debt [Line Items]
Short-term debt		$ 0		$ 0
Commercial paper		0		0
Obligations under reverse repurchase agreements	[1]	0		$ 0		$ 262,000,000.0
Maturities of short-term funding agreements				overnight to up to five business days
364-day credit agreement
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		3,800,000,000		$ 3,800,000,000
Term of credit agreement				364 days
Expiration date of credit facilities				Jun. 30, 2020
Extension option term				1 year
Credit Facility Expiring In June 2024
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		2,750,000,000		$ 2,750,000,000
Term of credit agreement				5 years
Expiration date of credit facilities				Jun. 30, 2024
Line of credit facility potentially available increase in maximum borrowing capacity				$ 500,000,000
Credit Facility Expiring In June 2023
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		3,750,000,000		$ 3,750,000,000
Term of credit agreement				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 program
Short-term Debt [Line Items]
Maximum borrowing capacity under credit facilities		10,300,000,000		$ 10,300,000,000
Maturities of commercial paper range				overnight to up to 364 days
Short-term debt, average outstanding amount		$ 3,500,000,000	$ 3,800,000,000	$ 3,700,000,000	$ 3,800,000,000
Debt instrument, interest rate during period		1.70%	2.30%	2.00%	2.10%
Short Term Commercial Paper Program
Short-term Debt [Line Items]
Commercial paper weighted average maturity		2 days	2 days	2 days	2 days
Reverse repurchase agreements
Short-term Debt [Line Items]
Short-term debt, average outstanding amount		$ 335,900,000	$ 325,400,000	$ 381,200,000	$ 410,200,000
Debt instrument, interest rate during period		1.70%	1.90%	1.80%	1.80%

[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. Refer to Note 9