Loans (Textual) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($) Segment Loans BaordOfDirectors Tenants	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)
Loans (Textual) [Abstract]
Number of portfolio segment | Segment	2
Number of classes of loans | Loans	6
Number of minimum tenants under lease of non-owner occupied commercial real estate | Tenants	1
Number of members of the board of directors in loan committee | BaordOfDirectors	8
Minimum due period of loans consider in a nonperforming status	90 days
Total nonaccrual TDR loans	$ 32,400	$ 35,900	$ 35,700
Residential Mortgage Loans in Process of Foreclosure	900	2,900	2,000
Difference between recorded investment and unpaid principal balance of loan	22,000	25,300	30,200
Confirmed losses (partial charge-offs)	16,300	17,100	15,200
Fair value of discount adjustment	5,700	8,200	15,000
Acquired impaired loans	12,500	12,800	15,900
Performing trouble debt restructuring under impaired loans	49,400	47,800	45,800
Financing Receivable, Modifications, Recorded Investment	98,232	103,111	99,428
Commercial Loan Portfolio [Member]
Loans (Textual) [Abstract]
Minimum value of loan requires executive and senior officer approval	1,500
Financing Receivable, Modifications, Recorded Investment	$ 74,085	78,823	74,751
Consumer Portfolio Segment [Member]
Loans (Textual) [Abstract]
Maximum due period of loans consider in performing status	90 days
Minimum due period of loans consider in a nonperforming status	90 days
Financing Receivable, Modifications, Recorded Investment	$ 24,147	$ 24,288	$ 24,677
Commercial [Member]
Loans (Textual) [Abstract]
Minimum value of loan requires group loan authority approval	1,000
Maximum value of loan requires executive and senior officer approval	$ 3,500
Real Estate Residential Loans [Member]
Loans (Textual) [Abstract]
Period for loan secured under real estate residential security	15 years
Loan-to-value ratio at the time of origination	80.00%
Land Development Loans [Member]
Loans (Textual) [Abstract]
Maximum period for payment of loan	12 months
Maximum [Member] | Commercial Loan Portfolio [Member]
Loans (Textual) [Abstract]
Maximum value of loan requires group loan authority approval	$ 10,000
Other loans requiring director loan committee approval depending on risk rating and credit action required	$ 10,000
Maximum [Member] | Real Estate Residential Loans [Member]
Loans (Textual) [Abstract]
Upper limit of number of family residential properties | Tenants	4
Minimum [Member] | Commercial Loan Portfolio [Member]
Loans (Textual) [Abstract]
Minimum value of loan requires group loan authority approval	$ 1,000
Minimum value of loans depending on risk rating and requires credit action from board of directors	15,000
Minimum [Member] | Commercial [Member]
Loans (Textual) [Abstract]
Minimum value of loans requiring only director loan committee approval	$ 10,000
Minimum [Member] | Real Estate Residential Loans [Member]
Loans (Textual) [Abstract]
Lower limit of number of family residential properties | Tenants	1