Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 174,147	$ 171,769
Accumulated Amortization	(103,562)	(94,696)
Valuation Allowance	0	(83)
Net Intangible Assets	70,585	76,990
Loan servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	89,732	87,354
Accumulated Amortization	(66,406)	(63,161)
Valuation Allowance	0	(83)
Net Intangible Assets	23,326	24,110
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	80,470	80,470
Accumulated Amortization	(34,640)	(29,136)
Valuation Allowance	0	0
Net Intangible Assets	45,830	51,334
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	3,945	3,945
Accumulated Amortization	(2,516)	(2,399)
Valuation Allowance	0	0
Net Intangible Assets	$ 1,429	$ 1,546