Comprehensive Income: Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	$ (1,819)	$ (1,197)
Other comprehensive income (loss)	512	(622)	$ 223
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(1,307)	(1,819)	(1,197)
Interest Rate Swaps, Cash Flow Hedges, AOCI [Member] | Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	(1,018)	(719)
Other comprehensive income (loss)	383	(299)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(635)	(1,018)	(719)
Employee Benefit Plans, AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	(801)	(478)
Other comprehensive income (loss)	129	(323)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	$ (672)	$ (801)	$ (478)