Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 217,083	$ 208,255
Accumulated Amortization	(154,558)	(136,941)
Valuation Allowance	0	(865)
Net Intangible Assets	62,525	70,449
Loan servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	111,978	103,150
Accumulated Amortization	(89,039)	(80,340)
Valuation Allowance	0	(865)
Net Intangible Assets	22,939	21,945
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	101,160	101,160
Accumulated Amortization	(62,511)	(53,747)
Valuation Allowance	0	0
Net Intangible Assets	38,649	47,413
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	3,945	3,945
Accumulated Amortization	(3,008)	(2,854)
Valuation Allowance	0	0
Net Intangible Assets	$ 937	$ 1,091