Mortgage Servicing Rights - Narrative (Details) - Mortgage loans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Mortgage servicing rights, fair value	$ 37.4	$ 28.2
Servicing asset at fair value, assumptions used to estimate fair value, weighted average life	7 years 7 months 6 days	5 years 10 months 24 days
Impairment reversals	$ (3.4)	$ (6.9)	$ (9.9)
Permanent impairment charged against carrying value	$ 0.0
Minimum
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Servicing assets at fair value, assumptions used to estimate fair value, discount rate	11.80%	8.60%
Servicing assets at fair value, assumptions used to estimate fair value, prepayment speed	0.50%	0.70%
Maximum [Member]
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Servicing assets at fair value, assumptions used to estimate fair value, discount rate	13.50%	10.40%
Servicing assets at fair value, assumptions used to estimate fair value, prepayment speed	3.40%	2.00%