Fair Value Disclosures - Assets Measured at Fair Value on a Non-recurring Basis (Details 3) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Assets measured at fair value on a non-recurring basis
Impaired loans held for investment	$ 40,065	$ 39,948
Mortgage servicing rights	3,182	2,739
Other real estate owned	3,301	6,600
Total	46,548	49,287
Level 1 [Member]
Assets measured at fair value on a non-recurring basis
Impaired loans held for investment
Mortgage servicing rights
Other real estate owned
Total
Level 2 [Member]
Assets measured at fair value on a non-recurring basis
Mortgage servicing rights	3,182	2,739
Other real estate owned	3,301	6,600
Total	6,483	9,339
Level 3 [Member]
Assets measured at fair value on a non-recurring basis
Impaired loans held for investment	40,065	39,948
Total	$ 40,065	$ 39,948