Fair Value Measurements (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair values and unrealized losses on securities available-for-sale
Less than Twelve Months, Estimated fair value	$ 9,529	$ 18,218
Less than Twelve Months, Gross unrealized losses	(8)	(19)
Twelve Months or More, Estimated fair value
Twelve Months or More, Gross unrealized Losses
Estimated fair value, Total	9,529	18,218
Gross unrealized losses, Total	(8)	(19)
U.S. government obligations [Member]
Fair values and unrealized losses on securities available-for-sale
Less than Twelve Months, Estimated fair value
Less than Twelve Months, Gross unrealized losses
Twelve Months or More, Estimated fair value
Twelve Months or More, Gross unrealized Losses
Estimated fair value, Total
Gross unrealized losses, Total
Municipal securities [Member]
Fair values and unrealized losses on securities available-for-sale
Less than Twelve Months, Estimated fair value	9,529	18,218
Less than Twelve Months, Gross unrealized losses	(8)	(19)
Twelve Months or More, Estimated fair value
Twelve Months or More, Gross unrealized Losses
Estimated fair value, Total	9,529	18,218
Gross unrealized losses, Total	(8)	(19)
Corporate bonds [Member]
Fair values and unrealized losses on securities available-for-sale
Less than Twelve Months, Estimated fair value
Less than Twelve Months, Gross unrealized losses
Twelve Months or More, Estimated fair value
Twelve Months or More, Gross unrealized Losses
Estimated fair value, Total
Gross unrealized losses, Total