Income Taxes - Schedule of Net Deferred Tax liability (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan losses	$ 6,865	$ 6,264
Amortization of core deposit intangible	898	759
Deferred compensation	4,448	6,158
Unrealized loss on available-for-sale debt securities	4,563	988
Other	3,222	3,599
Subtotal	19,996	17,768
Deferred tax liabilities:
FHLB stock dividends	(550)	(550)
Depreciation	(4,322)	(4,115)
Cash flow hedges	(930)
Mortgage servicing rights	(28,518)	(19,830)
Other	(5,969)	(5,131)
Subtotal	(40,289)	(29,626)
Net deferred tax liability	$ (20,293)	$ (11,858)