Loans, Troubled Debt Restructurings Performing and Nonaccrual (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	$ 76,501	$ 74,618
Nonaccrual Restructured Loans	23,827	23,486
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	29,580	30,047
Nonaccrual Restructured Loans	886	1,776
Commercial real estate — owner occupied
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	3,892	3,989
Nonaccrual Restructured Loans	0	0
Commercial real estate — investor
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	13,683	14,389
Nonaccrual Restructured Loans	1,007	0
Real estate construction
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	305	310
Nonaccrual Restructured Loans	152	157
Residential mortgage
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	19,902	17,068
Nonaccrual Restructured Loans	18,640	18,991
Home equity
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	8,098	7,705
Nonaccrual Restructured Loans	3,117	2,537
Other consumer
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	1,041	1,110
Nonaccrual Restructured Loans	$ 25	$ 25