Investments - Schedule of Loans by Ratio (Details) $ in Millions	Sep. 30, 2022 USD ($) security loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 158.8
Loan Count | loan	28
Equal to or less than 50.0%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 35.6
Loan Count | security	6
Greater than 50.0% to 55.0%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 9.1
Loan Count | security	2
Greater than 55.0% to 60.0%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 42.6
Loan Count | security	8
Greater than 60.0% to 70.0%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 71.5
Loan Count | security	12
1.00 to 1.50
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 10.4
Loan Count | security	2
Greater than 1.5 to 2.0
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 59.3
Loan Count | security	10
Greater than 2.0 to 3.0
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 52.0
Loan Count | security	10
Greater than 3.0 to 4.0
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 25.8
Loan Count | security	4
Greater than 4.0
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cost	$ 11.3
Loan Count | security	2