Loans, Troubled Debt Restructurings Performing and Nonaccrual (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	$ 79,857	$ 87,363	$ 98,216
Nonaccrual Restructured Loans	29,385	37,684	57,656
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	31,884	29,293	33,892
Nonaccrual Restructured Loans	1,276	1,714	3,260
Commercial real estate — owner occupied
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	5,490	7,877	10,454
Nonaccrual Restructured Loans	2,220	2,703	5,656
Commercial real estate — investor
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	15,289	21,915	23,127
Nonaccrual Restructured Loans	924	3,936	15,216
Real estate construction
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	359	510	727
Nonaccrual Restructured Loans	150	177	2,438
Residential mortgage
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	18,100	19,870	20,833
Nonaccrual Restructured Loans	21,906	24,592	26,049
Home equity
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	7,756	7,069	8,209
Nonaccrual Restructured Loans	2,877	4,522	4,838
Other consumer
Financing Receivable, Modifications [Line Items]
Performing Restructured Loans	979	829	974
Nonaccrual Restructured Loans	$ 32	$ 40	$ 199