Loans, Troubled Debt Restructurings Performing and Nonaccrual (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	$ 53,263	$ 74,618	$ 79,857
Nonaccrual Restructured Loans	26,292	23,486	29,385
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	25,478	30,047	31,884
Nonaccrual Restructured Loans	249	1,776	1,276
Commercial real estate — owner occupied
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	2,080	3,989	5,490
Nonaccrual Restructured Loans	0	0	2,220
Commercial real estate — investor
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	799	14,389	15,289
Nonaccrual Restructured Loans	933	0	924
Real estate construction
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	311	310	359
Nonaccrual Restructured Loans	198	157	150
Residential mortgage
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	16,036	17,068	18,100
Nonaccrual Restructured Loans	22,279	18,991	21,906
Home equity
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	7,385	7,705	7,756
Nonaccrual Restructured Loans	2,627	2,537	2,877
Other consumer
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	1,174	1,110	979
Nonaccrual Restructured Loans	$ 6	$ 25	$ 32