Other Assets - Mortgage Servicing Rights - Quantitative Assumptions Used for MSRs (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Minimum
Quantitative assumptions used in determining lower of cost or fair value of MSRs
Conditional prepayment rate (as a percent)	6.87%	7.02%
Life in years (of the MSR)	4 years 3 months 18 days	3 years 4 months 6 days
Weighted-average coupon rate (as a percent)	3.57%	3.55%
Discount rate (as a percent)	10.40%	10.41%
Maximum
Quantitative assumptions used in determining lower of cost or fair value of MSRs
Conditional prepayment rate (as a percent)	11.53%	13.58%
Life in years (of the MSR)	7 years 2 months 19 days	7 years 4 months 13 days
Weighted-average coupon rate (as a percent)	5.81%	6.24%
Discount rate (as a percent)	10.60%	10.54%
Weighted Average
Quantitative assumptions used in determining lower of cost or fair value of MSRs
Conditional prepayment rate (as a percent)	7.04%	7.11%
Life in years (of the MSR)	7 years 1 month 2 days	7 years 2 months 12 days
Weighted-average coupon rate (as a percent)	3.73%	3.68%
Discount rate (as a percent)	10.52%	10.51%