Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financial assets:
Cash and cash equivalents	$ 45,621	$ 44,996
Securities	877,238	849,620
Loans held for sale	5,132	6,371
Loans, net	1,896,605	1,734,609
Restricted investments in bank stock	21,660	20,564
Accrued interest receivable	7,553	7,059
Financial liabilities:
Deposits	2,334,469	2,241,179
Short-term borrowings	359,200	277,750
Long-term debt		12,642
Accrued interest payable	260	218
Commitments to Extend Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Standby Letters of Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Quoted Prices in Active Markets for Identical Assets, Level 1 [Member]
Financial assets:
Cash and cash equivalents	45,621	44,996
Securities	0	0
Loans held for sale	0	0
Loans, net	0	0
Restricted investments in bank stock	0	0
Accrued interest receivable	7,553	7,059
Financial liabilities:
Deposits	0	0
Short-term borrowings	359,200	277,750
Long-term debt		0
Accrued interest payable	260	218
Quoted Prices in Active Markets for Identical Assets, Level 1 [Member] | Commitments to Extend Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Quoted Prices in Active Markets for Identical Assets, Level 1 [Member] | Standby Letters of Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Significant Other Observable Inputs, Level 2 [Member]
Financial assets:
Cash and cash equivalents	0	0
Securities	877,238	849,620
Loans held for sale	0	0
Loans, net	0	0
Restricted investments in bank stock	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Short-term borrowings	0	0
Long-term debt		0
Accrued interest payable	0	0
Significant Other Observable Inputs, Level 2 [Member] | Commitments to Extend Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Significant Other Observable Inputs, Level 2 [Member] | Standby Letters of Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Significant Unobservable Inputs, Level 3 [Member]
Financial assets:
Cash and cash equivalents	0	0
Securities	0	0
Loans held for sale	5,132	6,371
Loans, net	1,896,605	1,734,609
Restricted investments in bank stock	21,660	20,564
Accrued interest receivable	0	0
Financial liabilities:
Deposits	2,334,469	2,241,179
Short-term borrowings	0	0
Long-term debt		12,642
Accrued interest payable	0	0
Significant Unobservable Inputs, Level 3 [Member] | Commitments to Extend Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Significant Unobservable Inputs, Level 3 [Member] | Standby Letters of Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	45,621	44,996
Securities	887,515	869,737
Loans held for sale	5,088	6,225
Loans, net	1,889,080	1,727,762
Restricted investments in bank stock	21,660	20,564
Accrued interest receivable	7,553	7,059
Financial liabilities:
Deposits	2,331,849	2,239,621
Short-term borrowings	359,200	277,750
Long-term debt		15,800
Accrued interest payable	260	218
Carrying Amount [Member] | Commitments to Extend Credit [Member]
Financial liabilities:
Off-balance sheet instruments	0	0
Carrying Amount [Member] | Standby Letters of Credit [Member]
Financial liabilities:
Off-balance sheet instruments	$ 0	$ 0