Income Tax - Deferred tax assets and liabilities - (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets
Allowance for loan losses	$ 1,358	$ 1,523
Deferred compensation	455	412
Purchase accounting adjustments	834	29
Non-accrual interest	111	60
Real estate held for sale	237	120
AMT	89	112
Other	72	20
Total assets	3,156	2,276
Liabilities
Depreciation and amortization	(572)	(849)
Loan fees	(184)	(183)
Mortgage servicing rights	(259)	(244)
Federal Home Loan Bank stock dividends	(92)	(87)
Prepaid expenses	(220)	(157)
Available-for-sale securities	(1,053)	(1,008)
Pension and employee benefits	(64)	(55)
Intangibles	(192)	(2)
Other	(102)	(48)
Total liabilities	(2,738)	(2,633)
Deferred tax assets, net	$ 418	$ (357)