Corporate Investments and Funds Held For Clients (Narrative) (Details) - USD ($)	9 Months Ended
	Mar. 31, 2022	Jun. 30, 2021
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 28,250,800,000	$ 24,371,700,000
Client fund obligation repayment period	1 year
Client funds obligations	$ 59,387,900,000	34,403,800,000
Client funds held in grantor trust	$ 53,200,800,000	31,092,300,000
Client funds investments with original maturities	ninety days or less
Fair Value, Inputs, Level 1
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 0
Fair Value, Inputs, Level 3
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	0
Asset-Backed Auto Loan Receivables
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	1,011,900,000
Fixed Rate Credit Card
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	688,900,000
Asset-Backed Equipment Lease Receivable
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	233,400,000
Rate Reduction
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	50,900,000
Federal Farm Credit Banks
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	1,026,000,000
Federal Home Loan Banks
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	544,400,000
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	862,800,000	$ 834,600,000
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	536,900,000
Debt Security, Corporate, Non-US
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 274,900,000