Other Comprehensive Income: Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	$ (20,084)	$ (27,346)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(15,567)	(20,084)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	(11,176)	(14,790)
Other comprehensive income (loss), before reclassifications	4,604	1,959
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(6,112)	(11,176)
Accumulated Defined Benefit Plans Adjustment \| Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	460	1,655
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications	3,973	4,982
Accumulated Other Comprehensive Income (Loss) \| Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	544	2,280
Interest Rate Swap \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	(10,384)	(12,558)
Other comprehensive income (loss), before reclassifications	0	0
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(8,255)	(10,384)
Interest Rate Swap \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges \| Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	2,129	2,174
Commodity Contract \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	1,476	2
Other comprehensive income (loss), before reclassifications	(631)	3,023
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(1,200)	1,476
Commodity Contract \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges \| Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	$ (2,045)	$ (1,549)