Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 205,561	$ 199,932
Accumulated Amortization	(130,675)	(113,113)
Valuation Allowance	(1,013)	(47)
Net Intangible Assets	73,873	86,772
Loan servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	100,456	94,827
Accumulated Amortization	(77,404)	(70,095)
Valuation Allowance	(1,013)	(47)
Net Intangible Assets	22,039	24,685
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	101,160	101,160
Accumulated Amortization	(50,472)	(40,384)
Valuation Allowance	0	0
Net Intangible Assets	50,688	60,776
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	3,945	3,945
Accumulated Amortization	(2,799)	(2,634)
Valuation Allowance	0	0
Net Intangible Assets	$ 1,146	$ 1,311