Acquisition and Divestiture Activity (Fair Value and Unpaid Principal Balance of Loans Acquired) (Details) - BBVA USA Bancshares, Inc. $ in Thousands	Jun. 01, 2021 USD ($)
Business Acquisition [Line Items]
Net loans	$ 61,370,000
Carrying Amount
Business Acquisition [Line Items]
Net loans	62,269,000
Fair Value
Business Acquisition [Line Items]
Net loans	61,370,000
Total commercial | Carrying Amount
Business Acquisition [Line Items]
Net loans	40,544,000
Total commercial | Fair Value
Business Acquisition [Line Items]
Net loans	39,670,000
Total commercial | Commercial and industrial | Carrying Amount
Business Acquisition [Line Items]
Net loans	29,864,000
Total commercial | Commercial and industrial | Fair Value
Business Acquisition [Line Items]
Net loans	29,372,000
Total commercial | Commercial real estate | Carrying Amount
Business Acquisition [Line Items]
Net loans	10,632,000
Total commercial | Commercial real estate | Fair Value
Business Acquisition [Line Items]
Net loans	10,250,000
Total commercial | Equipment lease financing | Carrying Amount
Business Acquisition [Line Items]
Net loans	48,000
Total commercial | Equipment lease financing | Fair Value
Business Acquisition [Line Items]
Net loans	48,000
Total consumer | Carrying Amount
Business Acquisition [Line Items]
Net loans	21,725,000
Total consumer | Fair Value
Business Acquisition [Line Items]
Net loans	21,700,000
Total consumer | Residential real estate | Carrying Amount
Business Acquisition [Line Items]
Net loans	12,871,000
Total consumer | Residential real estate | Fair Value
Business Acquisition [Line Items]
Net loans	12,983,000
Total consumer | Home equity | Carrying Amount
Business Acquisition [Line Items]
Net loans	2,430,000
Total consumer | Home equity | Fair Value
Business Acquisition [Line Items]
Net loans	2,417,000
Total consumer | Automobile | Carrying Amount
Business Acquisition [Line Items]
Net loans	3,916,000
Total consumer | Automobile | Fair Value
Business Acquisition [Line Items]
Net loans	3,912,000
Total consumer | Credit card | Carrying Amount
Business Acquisition [Line Items]
Net loans	820,000
Total consumer | Credit card | Fair Value
Business Acquisition [Line Items]
Net loans	758,000
Total consumer | Other consumer | Carrying Amount
Business Acquisition [Line Items]
Net loans	1,688,000
Total consumer | Other consumer | Fair Value
Business Acquisition [Line Items]
Net loans	$ 1,630,000