Premises and Equipment (Major Classifications) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,313,049	$ 2,261,459
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,079,631	1,010,176
Property, Plant and Equipment, Net	1,233,418	1,251,283
Depreciation	106,585	108,641	$ 103,828
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	334,375	336,258
Premises and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,307,502	1,286,092
Furniture, equipment and software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 671,172	$ 639,109