Earnings Per Common Share: Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Details
Earnings per share net income	$ 45,342	$ 46,502	$ 43,529
Net Income Available to Common Shareholders	$ 45,342	$ 45,948	$ 42,950
Weighted Average Number of Shares Outstanding, Basic	13,912	13,818	13,700
Average common share stock options outstanding	229	182	176
Weighted Average Number of Shares Outstanding, Diluted	14,141	14,000	13,876
Basic	$ 3.26	$ 3.33	$ 3.14
Diluted	$ 3.21	$ 3.28	$ 3.10