Corporate Investments and Funds Held For Clients - Narrative (Details) - USD ($)	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 31,207,500,000	$ 29,764,900,000
Client fund obligation repayment period	1 year
Client funds obligations	$ 39,503,900,000	38,538,600,000
Funds held for clients held-in grantor trust	$ 34,940,000,000
Client funds investments with original maturities	90 days
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	686,800,000
Fixed Rate Credit Card
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	413,300,000
Asset-Backed Equipment Lease Receivable
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	168,900,000
Federal Farm Credit Banks
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	951,800,000
Federal Home Loan Banks
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	473,600,000
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	500,800,000	$ 632,500,000
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	529,300,000
Debt Security, Corporate, Non-US
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	400,300,000
Supranational Bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 209,800,000