Premises and Equipment, Summary Composition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Cost	$ 745,375
Accumulated Depreciation	360,202
Net Book Value	385,173	$ 418,914
Depreciation and amortization	46,508	50,567	$ 58,149
Land
Property, Plant and Equipment [Line Items]
Cost	66,830
Accumulated Depreciation	0
Net Book Value	66,830	70,431
Land improvements
Property, Plant and Equipment [Line Items]
Cost	18,522
Accumulated Depreciation	8,967
Net Book Value	9,555	9,771
Buildings and improvements
Property, Plant and Equipment [Line Items]
Cost	386,859
Accumulated Depreciation	173,729
Net Book Value	213,130	222,162
Computers and related equipment
Property, Plant and Equipment [Line Items]
Cost	54,908
Accumulated Depreciation	41,076
Net Book Value	13,831	14,718
Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Cost	136,426
Accumulated Depreciation	94,639
Net Book Value	41,787	58,058
Operating leases
Property, Plant and Equipment [Line Items]
Cost	46,341
Accumulated Depreciation	18,042
Net Book Value	28,299	31,994
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	35,489
Accumulated Depreciation	23,748
Net Book Value	$ 11,741	$ 11,781