Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 89,796	$ 83,466	$ 71,498
Employee Benefits, net of tax:
Reclassifications of amortization of prior service credit and actuarial (gain) loss, net of tax of $18, $550 and $150, respectively	57	1,616	365
Net gain (loss), net of tax of $243, $93, and $(209), respectively	705	262	(578)
Cash Flow Hedges, net of tax:
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent		0	16
Total Other Comprehensive Income (Loss)	(2,682)	4,168	3,402
Comprehensive Income	87,114	87,634	74,900
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(2,453)	(3,169)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,453	3,169
Reclassifications of amortization of prior service credit and actuarial (gain) loss, net of tax of $18, $550 and $150, respectively	57	1,616	365
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	(705)	(262)	578
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(229)	7,337
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent		0	16
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Cash Flow Hedges, net of tax:
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	35	28	(44)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(35)	(28)	44
Accumulated (Gain) Loss from Commodity Contracts Cash Flows Hedges [Member]
Cash Flow Hedges, net of tax:
Net (loss) gain on commodity contract cash flow hedges, net of tax of $(369), $2,702 and $2,063, respectively		7,075	5,400
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(2,545)	(4,813)	(1,757)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,545	4,813	1,757
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(934)	7,075
Net (loss) gain on commodity contract cash flow hedges, net of tax of $(369), $2,702 and $2,063, respectively		7,075	$ 5,400
Accumulated (Gain) Loss from Interest Rate Swap Cash Flows Hedges
Cash Flow Hedges, net of tax:
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		28
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(28)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	$ 0	$ 0