Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net Income	$ 36,933	$ 34,466
Amortization of prior service cost, net of tax of $(5) and $(5), respectively	(14)	(14)
Net gain, net of tax of $28, $28, $53 and $55, respectively	(32)	(77)
Unrealized gain on commodity contract cash flow hedges, net of tax of $185 and $63, respectively	529	166
Unrealized gain/(loss) on interest rate swap cash flow hedges, net of tax of $2, $(14), $1 and $(14), respectively	0	(2)
Other comprehensive income (loss)	547	227
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 37,480	$ 34,693