Loans and Allowances for Credit Losses, Troubled Debt Restructurings, Modifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$ 9,115	$ 11,718	$ 24,368	$ 41,073
Troubled Debt Restructurings, Recorded Balance With Payment Default	20,899	33,850	23,030	35,937
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	8,540
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	689
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	9,096	11,700	23,785	32,100
Troubled Debt Restructurings, Recorded Balance With Payment Default	19,142	33,483	21,273	35,570
Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	1,598	2,088	3,275
Troubled Debt Restructurings, Recorded Balance With Payment Default	298	2,364	542	2,543
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	8,025	9,655	20,019	27,098
Troubled Debt Restructurings, Recorded Balance With Payment Default	18,586	30,721	20,473	32,592
Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,678	1,727
Troubled Debt Restructurings, Recorded Balance With Payment Default	258	398	258	435
Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	19	18	82	104
Troubled Debt Restructurings, Recorded Balance With Payment Default	11	38	11	38
Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0		0
Accruing [Member] | Commercial | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance With Payment Default			0
Accruing [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Payment Stream [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,377	2,063	5,331	14,818
Troubled Debt Restructurings, Recorded Balance With Payment Default	3,408	3,908	3,678	4,264
Nonaccrual [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	8,540
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Nonaccrual [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Nonaccrual [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	689
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Nonaccrual [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Nonaccrual [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,358	2,045	4,748	5,845
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,651	3,541	1,921	3,897
Nonaccrual [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	1,598	2,088	3,275
Troubled Debt Restructurings, Recorded Balance With Payment Default	298	2,364	542	2,543
Nonaccrual [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	287	0	982	843
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,095	779	1,121	919
Nonaccrual [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,678	1,727
Troubled Debt Restructurings, Recorded Balance With Payment Default	258	398	258	435
Nonaccrual [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	19	18	82	104
Troubled Debt Restructurings, Recorded Balance With Payment Default	11	38	11	38
Nonaccrual [Member] | Interest Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		748
Nonaccrual [Member] | Interest Rate [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		689
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		689
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		59
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		59
Nonaccrual [Member] | Interest Rate [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Payment Stream [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,586	2,624
Nonaccrual [Member] | Payment Stream [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,085	2,295
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,037	2,150
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	48	145
Nonaccrual [Member] | Payment Stream [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,377	615	3,745	11,446
Nonaccrual [Member] | Combination & Other [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,358	597	3,663	3,491
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	150	1,051	1,125
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	287	0	982	843
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,630	1,523
Nonaccrual [Member] | Combination & Other [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$ 19	$ 18	$ 82	$ 104