Loans (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Nonaccrual loans, segregated by loan class
Nonaccrual loans	$ 20,505	$ 21,418
Commercial [Member]
Nonaccrual loans, segregated by loan class
Nonaccrual loans	0	49
Commercial real estate: Construction [Member]
Nonaccrual loans, segregated by loan class
Nonaccrual loans	104	106
Commercial real estate: Other [Member]
Nonaccrual loans, segregated by loan class
Nonaccrual loans	6,160	6,104
Residential: 1-4 family [Member]
Nonaccrual loans, segregated by loan class
Nonaccrual loans	13,943	14,806
Residential: Home equities [Member]
Nonaccrual loans, segregated by loan class
Nonaccrual loans	$ 298	$ 353