Regulatory Capital - U.S. Basel III Regulatory Requirements (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Actual Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 3,085,133	$ 3,264,309
Tier 1 Capital (to Risk-Weighted Assets)	3,085,133	3,264,309
Total Capital (to Risk-Weighted Assets)	3,399,606	3,600,668
Tier 1 Capital (to Average Assets)	$ 3,085,133	$ 3,264,309
Actual Ratio
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	12.40%	12.20%
Tier 1 Capital (to Risk-Weighted Assets)	0.124	0.122
Total Capital (to Risk-Weighted Assets)	0.137	0.134
Tier 1 Capital (to Average Assets)	0.096	0.102
Advanced Approach
U.S. Basel III Regulatory Requirements, Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 1,735,574	$ 1,876,050
Tier 1 Capital (to Risk-Weighted Assets)	2,107,482	2,278,060
Total Capital (to Risk-Weighted Assets)	2,603,361	2,814,074
Tier 1 Capital (to Average Assets)	$ 1,284,390	$ 1,284,642
U.S. Basel III 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

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Amount of total capital as defined by regulatory framework.

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