Long-term Debt (Details) - USD ($)	6 Months Ended
	Dec. 31, 2018	Jun. 30, 2018
Debt Instrument [Line Items]
Aggregate principal amount	$ 2,000,000,000
Notes payable	2,012,000,000	$ 2,013,000,000
Less: current portion	(2,600,000)	(2,500,000)
Less: unamortized discount and debt issuance costs	(7,100,000)	(8,100,000)
Total long-term debt	2,002,300,000	2,002,400,000
Fair value of notes issued	$ 1,986,400,000
Fixed-rate 2.25% notes due September 15, 2020
Debt Instrument [Line Items]
Debt instrument, term	5 years
Debt instrument effective rate (percent)	2.37%
Notes payable	$ 1,000,000,000	1,000,000,000
Interest Rate	2.25%
Due Date	Sep. 15, 2020
Fixed-rate 3.375% notes due September 15, 2025
Debt Instrument [Line Items]
Debt instrument, term	10 years
Debt instrument effective rate (percent)	3.47%
Notes payable	$ 1,000,000,000	1,000,000,000
Interest Rate	3.375%
Due Date	Sep. 15, 2025
Other
Debt Instrument [Line Items]
Notes payable	$ 12,000,000	$ 13,000,000