Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Deferred tax liabilities:
Property, plant and equipment		$ (66,497)	$ (58,273)
Operating lease right-of-use assets		(8,716)	(9,370)
Identifiable intangibles		(3,565)	(6,802)
Investments		(29,962)	(34,604)
Derivative Instruments		(6,972)	(7,911)
Other		(5,826)	(5,160)
Deferred tax liabilities		(121,538)	(122,120)
Deferred tax assets:
Employee benefits		28,989	28,859
Accounts and notes receivable		10,406	6,726
Inventory		3,718	10,272
Federal income tax credits		3,439	1,914
Net operating loss carryforwards		1,015	1,740
Operating lease liability		8,653	9,526
Other		12,324	7,118
Total deferred tax assets		68,544	66,155
less: Valuation allowance		(4,416)	(3,834)
Net deferred tax assets		64,128	62,321
Net deferred tax liabilities	[1]	(57,410)	(59,799)
Other Assets [Member]
Deferred tax assets:
Net deferred tax assets		$ 1,200	$ 4,300

[1] The Company had deferred tax assets of $1.2 million and $4.3 million included in Other assets in the Consolidated Balance Sheets as of December 31, 2023 and 2022, respectively.