Bank subsidiary (Details 10) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Credit risk profile based on nonaccrual loans
Nonaccrual loans	$ 57,126	$ 64,887
Accruing loans 90 days or more past due	2,187	373
Residential 1-4 family
Credit risk profile based on nonaccrual loans
Nonaccrual loans	21,392	26,721
Commercial real estate
Credit risk profile based on nonaccrual loans
Nonaccrual loans	3,811	6,750
Home equity line of credit
Credit risk profile based on nonaccrual loans
Nonaccrual loans	2,160	2,349
Residential land
Credit risk profile based on nonaccrual loans
Nonaccrual loans	7,565	8,561
Accruing loans 90 days or more past due	2,187
Commercial loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	21,935	20,222
Accruing loans 90 days or more past due		131
Consumer loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	263	284
Accruing loans 90 days or more past due		$ 242