Variable Interest Entities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Sep. 30, 2024
Variable Interest Entity [Line Items]
Percentage of outstanding equity interests	50.00%
Maximum exposure to trusts				$ 36.4
Reimbursement obligation coverage percentage				12.00%
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Deposits assumed	$ 70.8	$ 158.7
Non-marketable investment carrying value	230.0		$ 216.5
Variable Interest Entity, Not Primary Beneficiary | Unfunded Loan Commitment
Variable Interest Entity [Line Items]
Maximum exposure to loss	$ 341.8		$ 332.8