Goodwill and Other Intangible Assets - Components of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 36,422	$ 35,734
Accumulated Amortization and Fair Value Adjustments	23,613	21,825
Net Carrying Amount	12,809	13,909
Covenants Not To Compete [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	710	710
Accumulated Amortization and Fair Value Adjustments	710	580
Net Carrying Amount	0	130
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,788	6,788
Accumulated Amortization and Fair Value Adjustments	2,663	2,135
Net Carrying Amount	4,125	4,653
Customer Related Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	12,381	12,381
Accumulated Amortization and Fair Value Adjustments	10,347	9,828
Net Carrying Amount	2,034	2,553
Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	16,543	15,855
Accumulated Amortization and Fair Value Adjustments	9,893	9,282
Net Carrying Amount	$ 6,650	$ 6,573