Mortgage Servicing Rights (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Mortgage Servicing Rights [Abstract]
Unpaid principal balances of loans serviced for FNMA	$ 365,700,000		$ 393,100,000
Summary of the Change in the Balance of Mortgage Service Rights Assets [Roll Forward]
Beginning balance, at fair value	2,437,000
Servicing rights that result from transfers of financial assets	(880,000)		(539,000)
Changes in fair value [Abstract]
Ending balance, at fair value	2,306,000		2,437,000
Mortgage Servicing Rights, Key Economic Assumptions [Abstract]
Mortgage servicing income	550,000		418,000
Mortgage Servicing Assets [Member]
Summary of the Change in the Balance of Mortgage Service Rights Assets [Roll Forward]
Beginning balance, at fair value	2,437,000		3,200,000
Servicing rights that result from transfers of financial assets	880,000		539,000
Changes in fair value [Abstract]
Due to changes in model inputs or assumptions(1)	53,000	[1]	(422,000)	[1]
Other	(1,064,000)	[2]	(880,000)	[2]
Ending balance, at fair value	$ 2,306,000		$ 2,437,000
Mortgage Servicing Rights, Key Economic Assumptions [Abstract]
Prepayment speed (PSA) (in hundredths)	357.00%		342.00%
Weighted-average life (years)	4 years 1 month 6 days		3 years 6 months
Yield to maturity discount rate (in hundredths)	10.00%		9.00%

[1] Represents changes in discount rates and prepayment speed assumptions, which are primarily affected by changes in interest rates

[2] Represents changes due to collection or realization of expected cash flows over time.