Goodwill and Other Intangible Assets (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Summary of finite-lived intangible assets
Gross Carrying Amount	$ 56,928	$ 49,962
Accumulated Amortization	(32,418)	(25,888)
Net Carrying Amount	24,510	24,074
Core deposit intangible
Summary of finite-lived intangible assets
Gross Carrying Amount	54,958	47,992
Accumulated Amortization	(31,586)	(25,188)
Net Carrying Amount	23,372	22,804
Customer relationship intangible
Summary of finite-lived intangible assets
Gross Carrying Amount	1,970	1,970
Accumulated Amortization	(832)	(700)
Net Carrying Amount	$ 1,138	$ 1,270