Earnings Per Share: Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Details
Net income	$ 3,705	$ 6,762	$ 10,369	$ 15,162
Weighted average shares, basic	3,720	3,733	3,722	3,730
Dilutive effect of stock options	17	20	16	22
Diluted shares	3,737	3,753	3,738	3,752
Earnings per share, basic	$ 1.00	$ 1.81	$ 2.79	$ 4.07
Earnings per share, diluted	$ 0.99	$ 1.80	$ 2.77	$ 4.04