Loans and Allowance for Loan Losses (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income on non-accrual loans outstanding	$ 3,300,000	$ 3,400,000
Interest income, cash basis method	1,700,000	554,000
Total loans	44,044,939,000		$ 43,716,353,000
Allowance for loan losses	457,010,000	414,956,000	443,424,000	$ 427,597,000
Reserve for unfunded commitments	57,500,000		57,500,000
All financing receivable, allowance for credit loss	514,500,000		$ 500,900,000
Allowance for credit loss, increase (decrease)	$ 13,600,000
ACL to loans ratio	1.17%		1.15%
Allowance for credit loss, reasonable and supportable forecast period	2 years
Allowance for credit loss, straight-line basis historical period	1 year
Allowance for credit loss, measurement input, estimated peak weighted average unemployment rate	5.30%		5.10%
Commitments to land additional funds to TDRs			$ 0
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	$ 0
Total consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-off of previously established reserves for credit losses associated with the transfer to held for sale	(6,600,000)
Reclassification to held-for-sale	424,100,000
Allowance for loan losses	$ 137,930,000	$ 141,538,000	138,299,000	$ 141,473,000
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loan substandard period (in days)	90 days
Loss
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loan charge off (in days)	120 days
Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 18,610,000,000		$ 16,090,000,000.00