Fair Value Measurements (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Financial assets, Carrying Amount
Cash and cash equivalents, Carrying Amount	$ 183,448	$ 127,742	$ 128,778	$ 77,964
Investment securities held to maturity, Carrying Amount	4,075	6,480
Loans, net, Carrying Amount	795,075	826,762
Financial liabilities, Carrying Amount
Deposits, Carrying Amount	1,038,514	1,009,919
Short-term borrowings, Carrying Amount	13,079	17,817
Long-term debt, Carrying Amount	455	455
Financial assets, Estimated Fair Value
Investment securities held to maturity, Estimated Fair Value	4,326	6,732
Fair Value, Inputs, Level 2 [Member]
Financial assets, Carrying Amount
Cash and cash equivalents, Carrying Amount	183,448	127,742
Investment securities held to maturity, Carrying Amount	4,075	6,480
Financial liabilities, Carrying Amount
Deposits, Carrying Amount	1,038,514	1,009,919
Short-term borrowings, Carrying Amount	13,079	17,817
Long-term debt, Carrying Amount	455	455
Financial assets, Estimated Fair Value
Cash and cash equivalents, Estimated Fair Value	183,448	127,742
Investment securities held to maturity, Estimated Fair Value	4,326	6,732
Financial liabilities, Estimated Fair Value
Deposits, Estimated Fair Value	1,042,244	1,013,964
Short-term borrowings, Estimated Fair Value	13,079	17,817
Long-term debt, Estimated Fair Value	455	470
Fair Value, Inputs, Level 3 [Member]
Financial assets, Carrying Amount
Loans, net, Carrying Amount	795,075	826,762
Financial assets, Estimated Fair Value
Loans, net, Estimated Fair Value	$ 821,480	$ 856,917