Investment Securities - Investments In Private Equity Funds Subject to Lock-Up Periods (Details) - Private equity funds $ in Millions	Mar. 31, 2023 USD ($)
Debt and Equity Securities, FV-NI [Line Items]
Fair Value	$ 159.4
1 – 3 years
Debt and Equity Securities, FV-NI [Line Items]
Fair Value	4.1
3 – 5 years
Debt and Equity Securities, FV-NI [Line Items]
Fair Value	18.6
5 – 10 years
Debt and Equity Securities, FV-NI [Line Items]
Fair Value	132.3
Greater than 10 years
Debt and Equity Securities, FV-NI [Line Items]
Fair Value	$ 4.4