Fair value measurements (Details 4) (Fair Value, Inputs, Level 3, USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Residential loan | Fair value of property or collateral
Fair value measurements
Fair value	$ 13,840
Residential loan | Fair value of property or collateral | Minimum
Fair value measurements
Appraised value (as a percent)	13.00%
Residential loan | Fair value of property or collateral | Maximum
Fair value measurements
Appraised value (as a percent)	96.00%
Home equity line of credit | Fair value of property or collateral
Fair value measurements
Fair value	536
Home equity line of credit | Fair value of property or collateral | Minimum
Fair value measurements
Appraised value (as a percent)	25.00%
Home equity line of credit | Fair value of property or collateral | Maximum
Fair value measurements
Appraised value (as a percent)	82.00%
Commercial loans
Fair value measurements
Fair value	2,851
Commercial loan 1 | Fair value of property or collateral
Fair value measurements
Fair value	220
Insurance proceeds (as a percent)	59.00%
Commercial loan 2 | Fair value of property or collateral
Fair value measurements
Fair value	892
Commercial loan 2 | Fair value of property or collateral | Minimum
Fair value measurements
Fair value of business assets (as a percent)	37.00%
Commercial loan 2 | Fair value of property or collateral | Maximum
Fair value measurements
Fair value of business assets (as a percent)	92.00%
Commercial loan 3 | Discounted cash flow
Fair value measurements
Fair value	1,739
Present value of expected future cash flows based on anticipated debt restructuring (as a percent)	59.00%
Discount rate (as a percent)	4.50%
Real estate acquired in settlement of loans | Fair value of property or collateral
Fair value measurements
Fair value	$ 2,036
Real estate acquired in settlement of loans | Fair value of property or collateral | Minimum
Fair value measurements
Appraised value (as a percent)	81.00%
Real estate acquired in settlement of loans | Fair value of property or collateral | Maximum
Fair value measurements
Appraised value (as a percent)	100.00%