Goodwill and Other Intangible Assets - Schedule of Mortgage Servicing Rights at Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 137,774
Finite-Lived Intangible Assets, Accumulated Amortization	69,613	64,608
Finite-Lived Intangible Assets, Net	68,161	73,166
Mortgage servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14,636	13,612
Finite-Lived Intangible Assets, Accumulated Amortization	5,102	4,806
Finite-Lived Intangible Assets, Net	$ 9,534	$ 8,806