Loans (Textual) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 Loans Segment BaordOfDirectors Tenants employee	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual TDRs Reported in Nonaccrual Loans	$ 37,200,000	$ 37,300,000
Number of portfolio segment	2
Number of classes of loans	7
Minimum number of tenants leased to for non-owner occupied real estate	1
Loans held-for-sale, at fair value	9,128,000	5,219,000
Number of bank executives and senior officers with credit decision limits similar to group loan authorities	4
Number of members of the board of directors in loan committee	8
Minimum due period of loans consider in a nonperforming status	90 days
Interest income recognized on nonaccrual loans while in accruing status	500,000	900,000	1,100,000
Interest lost on nonaccrual loans	3,300,000	3,500,000	4,500,000
Interest income recognized on TDRs	3,600,000	3,200,000	2,900,000
Difference between recorded investment and unpaid principal balance of loan	30,600,000	24,000,000
Confirmed losses (partial charge-offs)	15,400,000	20,200,000
Fair value of discount adjustment	15,200,000	3,800,000
Financing receivable allowance for acquired loans	500,000	500,000
Allowance for loan losses related to loans acquired with deteriorated credit quality	500,000	500,000
Reclassification from nonaccretable difference	10,000,000	125,000
Management [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to directors, executive officers and affiliates	31,200,000	26,800,000
Loans to directors, executive officers and affiliates, current year additions	39,300,000	54,200,000
Loans to directors, executive officers and affiliates, current year reductions	34,900,000	43,400,000
Commercial Loan Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum value of loan requires executive and senior officer approval	1,500,000
Minimum due period of loans consider in a nonperforming status	90 days
Allowance for loan losses related to loans acquired with deteriorated credit quality	0	0
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Original contractual terms	90 days
Minimum due period of loans consider in a nonperforming status	90 days
Allowance for loan losses related to loans acquired with deteriorated credit quality	500,000	500,000
Acquired Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Loans	19,900,000	9,800,000
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum value of loan requires group loan authority approval	1,000,000
Maximum value of loan requires executive and senior officer approval	3,500,000
Real Estate Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period for loan secured under real estate residential security	15 years
Loan-to-value ratio at the time of origination	80.00%
Loans held-for-sale, recorded investment sold	149,000,000	211,000,000
Land Development Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum period for payment of loan	12 months
Maximum [Member] | Commercial Loan Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum value of loan requires group loan authority approval	5,000,000
Other loans requiring director loan committee approval depending on risk rating and credit action required	5,000,000
Maximum [Member] | Real Estate Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Upper limit of number of family residential properties	4
Minimum [Member] | Commercial Loan Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum value of loan requires group loan authority approval	1,000,000
Minimum value of loans requiring board of directors approval	10,000,000
Minimum [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum value of loan requiring director loan committee approval	5,000,000
Minimum [Member] | Real Estate Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lower limit of number of family residential properties	1
Fixed-Rate Real Estate Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale, at fair value	9,100,000	5,200,000
Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Loans	45,700,000	39,600,000
Total Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	127,876,000	121,021,000	133,000,000
Impaired Financing Receivable, Interest Income, Accrual Method	4,353,000	3,764,000	3,700,000
Impaired Loans	134,667,000	129,345,000
Total Impaired Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	41,137,000	29,629,000	27,700,000
Impaired Financing Receivable, Interest Income, Accrual Method	1,375,000	990,000	1,000,000
Impaired Loans	39,060,000	41,355,000
Total Impaired Loans [Member] | Real Estate Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	26,745,000	26,836,000	33,400,000
Impaired Financing Receivable, Interest Income, Accrual Method	1,267,000	1,123,000	1,400,000
Impaired Loans	27,675,000	26,329,000
Total Impaired Loans [Member] | Land Development Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	3,551,000	9,794,000	9,100,000
Impaired Financing Receivable, Interest Income, Accrual Method	131,000	303,000	400,000
Impaired Loans	1,928,000	7,170,000
Total Impaired Loans [Member] | Real Estate Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	53,375,000	50,825,000	58,100,000
Impaired Financing Receivable, Interest Income, Accrual Method	1,567,000	1,348,000	1,000,000
Impaired Loans	63,203,000	50,796,000
Total Impaired Loans [Member] | Real Estate Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	164,000	370,000	700,000
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Impaired Loans	162,000	371,000
Total Impaired Loans [Member] | Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	602,000	653,000	1,100,000
Impaired Financing Receivable, Interest Income, Accrual Method	1,000	0
Impaired Loans	518,000	676,000
Total Impaired Loans [Member] | Home Equity Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment	2,302,000	2,914,000	2,900,000
Impaired Financing Receivable, Interest Income, Accrual Method	12,000	0
Impaired Loans	$ 2,121,000	$ 2,648,000