Summary of Significant Accounting Policies, Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	$ 1,065,939
Accumulated impairment and amortization	(627,191)
Balance	438,748
Balance (gross)	1,065,939	$ 1,065,939
Accumulated impairment and amortization	(627,191)	(627,191)
Balance	438,748	438,748
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Other intangible assets - gross	182,708	184,622
Accumulated amortization	(148,302)	(141,695)
Other intangible assets - net	34,406	42,927
Amortization of Intangible Assets	8,600	8,100	$ 7,600
Intangible Assets and liabilities, Estimated Amortization Expense, Fiscal Year Maturity [Abstract]
2025	8,500
2026	6,300
2027	5,000
2028	3,500
2029	3,500
Thereafter	$ 7,600
Weighted average amortization period for intangible assets and liabilities	6 years
Marine Transportation Segment [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	$ 505,784
Accumulated impairment and amortization	(237,626)
Balance	268,158
Balance (gross)	505,784	505,784
Accumulated impairment and amortization	(237,626)	(237,626)
Balance	268,158	268,158
Distribution and Services Segment [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	560,155
Accumulated impairment and amortization	(389,565)
Balance	170,590
Balance (gross)	560,155	560,155
Accumulated impairment and amortization	(389,565)	(389,565)
Balance	$ 170,590	$ 170,590