Income Taxes: Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Unrecognized tax benefits [Abstract]
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	$ 25	$ 217	$ 391
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	345	661	1,353
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(2,399)	0	0
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(314)	(2,113)	0
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	0	(194)	(436)
Unrecognized Tax Benefits	$ 1,772	$ 4,115	$ 5,544	$ 4,236