Segment Data (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment	2
Revenues [Abstract]
Revenues	$ 3,091,640	$ 2,784,754	$ 2,246,660
Segment profit (loss)	294,125	164,975	(290,601)
Total assets	5,722,197	5,554,924
Depreciation and amortization	211,156	201,443	213,718
Capital expenditures	401,730	172,606	98,015
Other segment disclosures [Abstract]
Gain on disposition of assets	5,009	8,279	5,761
Interest expense	(52,008)	(44,588)	(42,469)
Earnings (loss) before taxes on income	294,125	164,975	(290,601)
Other Assets [Abstract]
Investment in affiliates	2,576	2,171
Marine Transportation [Member]
Revenues [Abstract]
Revenues	1,721,937	1,616,967	1,322,918
Distribution and Services [Member]
Revenues [Abstract]
Revenues	1,369,703	1,167,787	923,742
Other [Member]
Revenues [Abstract]
Segment profit (loss)	(59,299)	(38,246)	(381,223)
Total assets	110,882	227,436
Depreciation and amortization	7,089	7,116	7,166
Capital expenditures	5,550	3,723	5,558
Other segment disclosures [Abstract]
General corporate expenses	(23,341)	(18,614)	(13,803)
Gain on disposition of assets	5,009	8,279	5,761
Impairments and other charges	0	0	(340,713)
Interest expense	(52,008)	(44,588)	(42,469)
Other income	11,041	16,677	10,001
Earnings (loss) before taxes on income	(59,299)	(38,246)	(381,223)
Other Assets [Abstract]
General corporate assets	108,306	225,265
Investment in affiliates	2,576	2,171
Total other assets	110,882	227,436
Reportable Segments [Member] | Marine Transportation [Member]
Revenues [Abstract]
Revenues	1,721,937	1,616,967	1,322,918
Segment profit (loss)	238,943	136,184	63,015
Total assets	4,454,931	4,285,647
Depreciation and amortization	184,225	177,551	185,979
Capital expenditures	255,411	147,170	84,353
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	238,943	136,184	63,015
Reportable Segments [Member] | Distribution and Services [Member]
Revenues [Abstract]
Revenues	1,369,703	1,167,787	923,742
Segment profit (loss)	114,481	67,037	27,607
Total assets	1,156,384	1,041,841
Depreciation and amortization	19,842	16,776	20,573
Capital expenditures	140,769	21,713	8,104
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	114,481	67,037	27,607
Intersegment Eliminations [Member]
Revenues [Abstract]
Revenues	39,800	31,900	23,600
Segment profit (loss)	4,000	3,200	2,400
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	$ 4,000	$ 3,200	$ 2,400