Foreclosed Property - Major classifications of foreclosed properties (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Classifications of foreclosed properties
Total foreclosed property	$ 7,538	$ 25,218	$ 42,293
Less valuation allowance	(3,602)	(6,954)	(11,872)
Foreclosed property, net	3,936	18,264	30,421
Balance as a percentage of original loan unpaid principal	31.60%	39.70%	39.30%
Commercial real estate
Classifications of foreclosed properties
Total foreclosed property	847	6,368	11,639
Commercial construction
Classifications of foreclosed properties
Total foreclosed property	376	2,204	2,732
Commercial
Classifications of foreclosed properties
Total foreclosed property	1,223	8,572	14,371
Residential mortgage
Classifications of foreclosed properties
Total foreclosed property	1,931	5,192	5,868
Residential construction
Classifications of foreclosed properties
Total foreclosed property	$ 4,384	$ 11,454	$ 22,054