Bank subsidiary (Details 12) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Credit risk profile based on nonaccrual loans
Nonaccrual loans	$ 64,887	$ 66,754
Accruing loans 90 days or more past due	373	541
Residential 1-4 family
Credit risk profile based on nonaccrual loans
Nonaccrual loans	26,721	28,298
Commercial real estate
Credit risk profile based on nonaccrual loans
Nonaccrual loans	6,750	3,436
Home equity line of credit
Credit risk profile based on nonaccrual loans
Nonaccrual loans	2,349	2,258
Residential land
Credit risk profile based on nonaccrual loans
Nonaccrual loans	8,561	14,535
Accruing loans 90 days or more past due		205
Commercial loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	20,222	17,946
Accruing loans 90 days or more past due	131	28
Consumer loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	284	281
Accruing loans 90 days or more past due	$ 242	$ 308