Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 83,466	$ 71,498	$ 65,153
Employee Benefits, net of tax:
Amortization of prior service cost, net of tax of $(20), $(18) and $(20), respectively	(57)	(59)	(57)
Net gain (loss), net of tax of $662, $(41), and $368, respectively	1,935	(154)	1,052
Cash Flow Hedges, net of tax:
Unrealized gain (loss) on commodity contract cash flow hedges, net of tax of $864, $1,392 and $(176), respectively	2,262	3,643	(434)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent	28	(28)
Total Other Comprehensive Income	4,168	3,402	561
Comprehensive Income	$ 87,634	$ 74,900	$ 65,714