Loans - Interest Recognized and Cash Basis Interest Earned on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 4,415	$ 5,943	$ 5,119	$ 5,970
Commercial
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	560	1,058	1,124	1,606
Consumer
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	3	5	3	5
Commercial | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	2,880	3,655	2,917	2,987
Land and construction | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	210	895	213	1,037
Home equity | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 762	$ 330	$ 862	$ 335