Fair Value of Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation for all assets and liabilities measured at fair value on a recurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	$ 1,718	$ 1,817	$ 1,718	$ 1,817
Total gains or losses (realized/unrealized):
Included in earnings	35	(6)	20	(25)
Included in other comprehensive income	147	(392)	49	167
Purchases, issuances, and settlements
Transfers in to/out of Level 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	1,900	1,419	1,969	1,561
Corporate bonds [Member]
Reconciliation for all assets and liabilities measured at fair value on a recurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	1,642	1,716	1,642	1,716
Total gains or losses (realized/unrealized):
Included in earnings
Included in other comprehensive income	147	(392)	49	167
Purchases, issuances, and settlements
Transfers in to/out of Level 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	1,789	1,324	1,838	1,491
Interest Rate Lock Commitments [Member]
Reconciliation for all assets and liabilities measured at fair value on a recurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	76	101	76	101
Total gains or losses (realized/unrealized):
Included in earnings	35	(6)	20	(25)
Included in other comprehensive income
Purchases, issuances, and settlements
Transfers in to/out of Level 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	$ 111	$ 95	$ 131	$ 70