Fair Value Disclosures and Reporting, the Fair Value Option and Fair Value Measurements (Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financial Assets:
Investment securities available for sale	$ 509,600	$ 511,883
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Cash and cash equivalents	48,988	50,095
Investment securities available for sale	$ 1,296	$ 2,222
Loans and leases, net held for investment
Collateral dependent impaired loans
Cash surrender value of life insurance policies
Other investments
Investment in limited partnership
Accrued interest receivable
Financial Liabilities:
Noninterest-bearing	$ 423,449	$ 390,897
Interest-bearing
Fed funds purchased and Repurchase agreements
Short-term borrowings
Long-term borrowings
Subordinated debentures
Limited partnership capital commitment
Accrued Interest Payable
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Cash and cash equivalents
Investment securities available for sale	$ 508,304	$ 509,661
Loans and leases, net held for investment	1,056,516	966,599
Collateral dependent impaired loans	9,943	4,791
Cash surrender value of life insurance policies	43,675	42,989
Other investments	7,546	7,042
Investment in limited partnership	6,432	7,276
Accrued interest receivable	$ 5,662	$ 5,852
Financial Liabilities:
Noninterest-bearing
Interest-bearing	$ 1,005,827	$ 976,002
Fed funds purchased and Repurchase agreements	10,115	7,251
Short-term borrowings	41,500	18,200
Long-term borrowings	2,004	6,000
Subordinated debentures	12,008	11,428
Limited partnership capital commitment	795	914
Accrued Interest Payable	$ 115	$ 137
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Cash and cash equivalents
Investment securities available for sale
Loans and leases, net held for investment
Collateral dependent impaired loans
Cash surrender value of life insurance policies
Other investments
Investment in limited partnership
Accrued interest receivable
Financial Liabilities:
Noninterest-bearing
Interest-bearing
Fed funds purchased and Repurchase agreements
Short-term borrowings
Long-term borrowings
Subordinated debentures
Limited partnership capital commitment
Accrued Interest Payable
Carrying Amount [Member]
Financial Assets:
Cash and cash equivalents	$ 48,988	$ 50,095
Investment securities available for sale	509,600	511,883
Loans and leases, net held for investment	1,035,731	956,265
Collateral dependent impaired loans	9,943	4,791
Cash surrender value of life insurance policies	43,675	42,989
Other investments	7,546	7,042
Investment in limited partnership	6,432	7,276
Accrued interest receivable	5,662	5,852
Financial Liabilities:
Noninterest-bearing	423,449	390,897
Interest-bearing	1,005,665	975,798
Fed funds purchased and Repurchase agreements	10,115	7,251
Short-term borrowings	41,500	18,200
Long-term borrowings	2,000	6,000
Subordinated debentures	30,928	30,928
Limited partnership capital commitment	795	914
Accrued Interest Payable	115	137
Fair Value [Member]
Financial Assets:
Cash and cash equivalents	48,988	50,095
Investment securities available for sale	509,600	511,883
Loans and leases, net held for investment	1,056,516	966,599
Collateral dependent impaired loans	9,943	4,791
Cash surrender value of life insurance policies	43,675	42,989
Other investments	7,546	7,042
Investment in limited partnership	6,432	7,276
Accrued interest receivable	5,662	5,852
Financial Liabilities:
Noninterest-bearing	423,449	390,897
Interest-bearing	1,005,827	976,002
Fed funds purchased and Repurchase agreements	10,115	7,251
Short-term borrowings	41,500	18,200
Long-term borrowings	2,004	6,000
Subordinated debentures	12,008	11,428
Limited partnership capital commitment	795	914
Accrued Interest Payable	$ 115	$ 137