Segment Data (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			2
Revenues [Abstract]
Revenues	$ 831,149	$ 764,772	$ 2,463,561	$ 2,292,464
Earnings before taxes on income	117,381	81,726	319,789	212,676
Total assets	5,870,723		5,870,723		$ 5,722,197
Other segment disclosures [Abstract]
Gain on disposition of assets	1,617	1,528	2,206	4,230
Interest expense	(12,498)	(13,386)	(38,468)	(38,893)
Earnings before taxes on income	117,381	81,726	319,789	212,676
Marine Transportation (KMT) [Member]
Revenues [Abstract]
Revenues	486,054	429,885	1,446,274	1,269,342
Distribution and Services [Member]
Revenues [Abstract]
Revenues	345,095	334,887	1,017,287	1,023,122
Other [Member]
Revenues [Abstract]
Earnings before taxes on income	(12,473)	(14,935)	(39,374)	(43,906)
Total assets	145,889		145,889		110,882
Other segment disclosures [Abstract]
General corporate expenses	(4,541)	(4,666)	(12,418)	(18,539)
Gain on disposition of assets	1,617	1,528	2,206	4,230
Interest expense	(12,498)	(13,386)	(38,468)	(38,893)
Other income	2,949	1,589	9,306	9,296
Earnings before taxes on income	(12,473)	(14,935)	(39,374)	(43,906)
Details of "Other" total assets [Abstract]
General corporate assets	143,276		143,276		108,306
Investment in affiliates	2,613		2,613		2,576
Total other assets	145,889		145,889		110,882
Reporting Segments [Member] | Marine Transportation (KMT) [Member]
Revenues [Abstract]
Revenues	486,054	429,885	1,446,274	1,269,342
Earnings before taxes on income	99,476	63,467	277,335	170,754
Total assets	4,547,989		4,547,989		4,454,931
Other segment disclosures [Abstract]
Earnings before taxes on income	99,476	63,467	277,335	170,754
Reporting Segments [Member] | Distribution and Services [Member]
Revenues [Abstract]
Revenues	345,095	334,887	1,017,287	1,023,122
Earnings before taxes on income	30,378	33,194	81,828	85,828
Total assets	1,176,845		1,176,845		$ 1,156,384
Other segment disclosures [Abstract]
Earnings before taxes on income	30,378	33,194	81,828	85,828
Intersegment Eliminations [Member]
Revenues [Abstract]
Revenues	5,000	9,900	19,100	29,600
Earnings before taxes on income	500	1,000	1,900	3,000
Other segment disclosures [Abstract]
Earnings before taxes on income	$ 500	$ 1,000	$ 1,900	$ 3,000