Loans - Interest Recognized and Cash Basis Interest Earned on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 5,428	$ 6,459
Commercial
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	1,343	1,907
Consumer
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	4	5
Commercial and residential | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	2,951	2,901
Land and construction | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	216	1,305
Home equity | Real estate
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 914	$ 341