Regulatory Capital - U.S. Basel III Regulatory Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Actual Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 3,040,662	$ 3,314,657
Tier 1 Capital (to Risk-Weighted Assets)	3,040,662	3,314,657
Total Capital (to Risk-Weighted Assets)	3,338,645	3,410,183
Tier 1 Capital (to Average Assets)	$ 3,040,662	$ 3,314,657
Actual Ratio
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	12.90%	14.10%
Tier 1 Capital (to Risk-Weighted Assets)	0.129	0.141
Total Capital (to Risk-Weighted Assets)	0.142	0.145
Tier 1 Capital (to Average Assets)	0.103	0.111
Well Capitalized Regulatory Requirements, Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 1,645,807	$ 1,643,132
Tier 1 Capital (to Risk-Weighted Assets)	1,998,480	1,995,232
Total Capital (to Risk-Weighted Assets)	2,468,711	2,464,699
Tier 1 Capital (to Average Assets)	$ 1,185,280	$ 1,198,808
Well Capitalized Regulatory Requirements, Ratio
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	7.00%	7.00%
Tier 1 Capital (to Risk-Weighted Assets)	0.085	0.085
Total Capital (to Risk-Weighted Assets)	0.105	0.105
Tier 1 Capital (to Average Assets)	0.040	0.040