Bank subsidiary (Details 9) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Credit risk profile based on nonaccrual loans
Nonaccrual loans	$ 57,655	$ 66,754
Accruing loans 90 days or more past due	2,956	541
Residential 1-4 family
Credit risk profile based on nonaccrual loans
Nonaccrual loans	29,613	28,298
Commercial real estate
Credit risk profile based on nonaccrual loans
Nonaccrual loans	2,929	3,436
Home equity line of credit
Credit risk profile based on nonaccrual loans
Nonaccrual loans	2,621	2,258
Residential land
Credit risk profile based on nonaccrual loans
Nonaccrual loans	4,393	14,535
Accruing loans 90 days or more past due	2,473	205
Commercial loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	17,856	17,946
Accruing loans 90 days or more past due	123	28
Consumer loans
Credit risk profile based on nonaccrual loans
Nonaccrual loans	243	281
Accruing loans 90 days or more past due	$ 360	$ 308