Regulatory Matters (Information On The Capital Ratios) (Detail) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 5,822,369	$ 2,804,290
Common Equity Tier One Capital Required for Capital Adequacy	$ 2,446,344	$ 1,076,871
Common Equity Tier One Capital Ratio	0.1071	0.1172
Common Equity Tier One Capital Required to be Well-Capitalized	$ 3,533,608	$ 1,555,480
Total risk-based capital, Actual Amount	$ 7,203,029	$ 3,265,064
Total risk-based capital, Actual Ratio	0.1325	0.1364
Total risk-based capital, Capital Requirements, Minimum Amount	$ 4,349,056	$ 1,914,436
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080	0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 5,436,320	$ 2,393,046
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100	0.100
Tier 1 risk-based capital, Actual Amount	$ 6,106,348	$ 2,949,327
Tier 1 risk-based capital, Actual Ratio	0.1123	0.1232
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 3,261,792	$ 1,435,827
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	0.060	0.060
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 4,349,056	$ 1,914,436
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	0.080	0.080
Tier 1 leverage capital, Actual Amount	$ 6,106,348	$ 2,949,327
Tier 1 leverage capital, Actual Ratio	0.0895	0.0847
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 2,730,212	$ 1,393,607
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	0.040	0.040
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 3,412,765	$ 1,742,008
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	0.050	0.050
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 6,661,504	$ 3,034,883
Common Equity Tier One Capital Required for Capital Adequacy	$ 2,442,058	$ 1,075,920
Common Equity Tier One Capital Ratio	0.1228	0.1269
Common Equity Tier One Capital Required to be Well-Capitalized	$ 3,527,417	$ 1,554,107
Total risk-based capital, Actual Amount	$ 7,165,935	$ 3,273,300
Total risk-based capital, Actual Ratio	0.1320	0.1369
Total risk-based capital, Capital Requirements, Minimum Amount	$ 4,341,437	$ 1,912,747
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080	0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 5,426,796	$ 2,390,934
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100	0.100
Tier 1 risk-based capital, Actual Amount	$ 6,661,504	$ 3,034,883
Tier 1 risk-based capital, Actual Ratio	0.1228	0.1269
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 3,256,078	$ 1,434,560
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	0.060	0.060
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 4,341,437	$ 1,912,747
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	0.080	0.080
Tier 1 leverage capital, Actual Amount	$ 6,661,504	$ 3,034,883
Tier 1 leverage capital, Actual Ratio	0.0977	0.0872
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 2,727,476	$ 1,392,821
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	0.040	0.040
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 3,409,345	$ 1,741,026
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	0.050	0.050
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045	0.045
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member] \| Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045	0.045
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065	0.065
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member] \| Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065	0.065

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