Revenue from Contracts with Customers (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Non-interest income		$ 139,427	$ 139,143	$ 271,196	$ 275,188
Total non-interest income from contracts with customers
Disaggregation of Revenue [Line Items]
Non-interest income		132,047	124,318	253,151	240,492
Total non-interest income from contracts with customers | Bank card transaction fees
Disaggregation of Revenue [Line Items]
Non-interest income		43,873	42,608	85,918	80,303
Total non-interest income from contracts with customers | Trust fees
Disaggregation of Revenue [Line Items]
Non-interest income		46,792	46,257	94,603	90,384
Total non-interest income from contracts with customers | Deposit account charges and other fees
Disaggregation of Revenue [Line Items]
Non-interest income		25,564	23,988	47,871	46,563
Total non-interest income from contracts with customers | Consumer brokerage services
Disaggregation of Revenue [Line Items]
Non-interest income		5,068	4,503	9,514	8,584
Total non-interest income from contracts with customers | Other non-interest income
Disaggregation of Revenue [Line Items]
Non-interest income		10,750	6,962	15,245	14,658
Other non-interest income (1)
Disaggregation of Revenue [Line Items]
Non-interest income	[1]	$ 7,380	$ 14,825	$ 18,045	$ 34,696

[1] This revenue is not within the scope of ASC 606, and includes fees relating to capital market activities, loan fees and sales, derivative instruments, standby letters of credit and various other transactions.