Federal Income Taxes: Reconciliation From Tax At the Statutory Rate to the Income Tax Provision (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Income Tax Disclosure [Abstract]      
Income tax expense at statutory rate $ 4,917 $ 5,790 $ 3,823
Tax exempt interest, net (38) (8) (21)
Change in valuation allowance (112) 19 (17,329)
Benefit of lower federal tax bracket (39) 0 0
Other, net 159 55 (16)
Total income tax expense (benefit) $ 4,887 $ 5,856 $ (13,543)