Loans and Allowance for Credit Losses Total Impaired Loans by Class Segments (Details) (USD $)																							3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Real-estate commercial mortage [Member]	Dec. 31, 2013 Real-estate commercial mortage [Member]	Mar. 31, 2014 Commercial - Secured [Member]	Dec. 31, 2013 Commercial - Secured [Member]	Mar. 31, 2014 Commercial - unsecured [Member]	Dec. 31, 2013 Commercial - unsecured [Member]	Mar. 31, 2014 Real-estate - home equity [Member]	Dec. 31, 2013 Real-estate - home equity [Member]	Mar. 31, 2014 Real-estate - residential mortgage [Member]	Dec. 31, 2013 Real-estate - residential mortgage [Member]	Mar. 31, 2014 Construction - commercial residential [Member]	Dec. 31, 2013 Construction - commercial residential [Member]	Mar. 31, 2014 Construction - Commercial [Member]	Dec. 31, 2013 Construction - Commercial [Member]	Mar. 31, 2014 Construction other [Member]	Dec. 31, 2013 Construction other [Member]	Mar. 31, 2014 Consumer - direct [Member]	Dec. 31, 2013 Consumer - direct [Member]	Mar. 31, 2014 Consumer - Indirect [Member]	Dec. 31, 2013 Consumer - Indirect [Member]	Mar. 31, 2014 Nonperforming Financing Receivable [Member]
Impaired Financing Receivables [Line Items]
Impaired Loans Balances, Real Estate as Collateral	$ 1,000,000
Financing Receivable, Recorded Investment, Days Outstanding																							90
Unpaid principal balance, with no related allowance	81,478,000	75,120,000	27,433,000	28,892,000	23,862,000	23,890,000			399,000	399,000	317,000	0	26,475,000	18,943,000	2,992,000	2,996,000
Unpaid principal balance, with related allowance	182,147,000	189,713,000	47,010,000	43,282,000	36,309,000	34,267,000	693,000	1,113,000	19,420,000	20,383,000	61,733,000	63,682,000	15,753,000	25,769,000	481,000	485,000	718,000	719,000	15,000	11,000	15,000	2,000
Unpaid Principal Balance	263,625,000	264,833,000
Recorded investment, with no related allowance	67,642,000	61,893,000	23,491,000	24,494,000	20,867,000	21,383,000			300,000	300,000	317,000	0	20,705,000	13,740,000	1,962,000	1,976,000
Recorded investment, with related allowance	133,747,000	139,971,000	38,407,000	35,830,000	23,765,000	22,324,000	641,000	1,048,000	13,854,000	14,337,000	51,365,000	51,097,000	4,963,000	14,579,000	191,000	195,000	544,000	548,000	15,000	11,000	2,000	2,000
Recorded Investment	201,389,000	201,864,000
Related Allowance	$ 63,901,000	$ 63,198,000	$ 16,394,000	$ 14,444,000	$ 13,232,000	$ 13,315,000	$ 472,000	$ 752,000	$ 9,491,000	$ 9,059,000	$ 21,711,000	$ 21,745,000	$ 2,212,000	$ 3,493,000	$ 76,000	$ 77,000	$ 298,000	$ 301,000	$ 13,000	$ 10,000	$ 2,000	$ 2,000