Loans - Interest Recognized and Cash Basis Interest Earned on Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 6,024	$ 9,040
Interest income during impairment	16	56
Commercial
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	1,774	4,069
Interest income during impairment	14	56
Real estate | Commercial and residential
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	3,006	2,758
Real estate | Land and construction
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	764	1,628
Real estate | Home equity
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	475	529
Interest income during impairment	2
Consumer
Interest Recognized and Cash Basis Interest Earned on Impaired Loans
Average of impaired loans during the period	$ 5	$ 56