Loans and Allowance for Credit Losses - Effects of Loan Modifications Made During the Period (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Interest Rate Reduction	21.30%	3.30%
Weighted-Average Months of Term Extension	8 months	7 months
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Months of Term Extension	10 months	10 months
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Interest Rate Reduction	1.40%	1.40%
Weighted-Average Months of Term Extension	89 months	111 months
Credit Card Receivable [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Interest Rate Reduction	16.40%	16.20%
Other Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Interest Rate Reduction	8.60%	7.30%
Weighted-Average Months of Term Extension	108 months	134 months
Loans Purchased From Government National Mortgage Association Mortgage Pools [Member]
Financing Receivable, Modifications [Line Items]
Weighted-Average Interest Rate Reduction	0.70%	0.70%
Weighted-Average Months of Term Extension	87 months	79 months