Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands		Dec. 31, 2024	Dec. 31, 2023
Deferred tax liabilities:
Property, plant and equipment		$ (64,934)	$ (66,497)
Operating lease right-of-use assets		(18,029)	(8,716)
Identifiable intangibles		0	(3,565)
Investments		(21,968)	(29,962)
Derivative Instruments		(7,202)	(6,972)
Other		(5,607)	(5,826)
Deferred tax liabilities		(117,740)	(121,538)
Deferred tax assets:
Employee benefits		24,346	28,989
Accounts and notes receivable		12,289	10,406
Inventory		3,166	3,718
Identifiable intangibles		655	0
Federal income tax credits		4,203	3,439
Net operating loss carryforwards		1,212	1,015
Operating lease liability		17,685	8,653
Other		7,402	12,324
Total deferred tax assets		70,958	68,544
less: Valuation allowance		(6,591)	(4,416)
Net deferred tax assets		64,367	64,128
Net deferred tax liabilities	[1]	(53,373)	(57,410)
Other Assets [Member]
Deferred tax assets:
Net deferred tax assets		$ 1,700	$ 1,200

[1] The Company had deferred tax assets of $1.7 million and $1.2 million included in Other assets in the Consolidated Balance Sheets as of December 31, 2024, and 2023, respectively.