CONDENSED STATEMENTS OF EARNINGS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues:
Revenues	$ 831,149	$ 764,772	$ 2,463,561	$ 2,292,464
Costs and expenses:
Costs of sales and operating expenses	552,091	530,541	1,657,004	1,618,690
Selling, general and administrative	84,119	79,125	254,708	250,870
Taxes, other than on income	8,973	9,666	27,327	28,610
Depreciation and amortization	60,653	53,445	177,777	156,251
Gain on disposition of assets	(1,617)	(1,528)	(2,206)	(4,230)
Total costs and expenses	704,219	671,249	2,114,610	2,050,191
Operating income	126,930	93,523	348,951	242,273
Other income	2,949	1,589	9,306	9,296
Interest expense	(12,498)	(13,386)	(38,468)	(38,893)
Earnings before taxes on income	117,381	81,726	319,789	212,676
Provision for taxes on income	(27,350)	(18,722)	(75,861)	(51,733)
Net earnings	90,031	63,004	243,928	160,943
Net (earnings) loss attributable to noncontrolling interests	(63)	(40)	(38)	86
Net earnings attributable to Kirby	$ 89,968	$ 62,964	$ 243,890	$ 161,029
Net earnings per share attributable to Kirby common stockholders:
Basic	$ 1.56	$ 1.06	$ 4.2	$ 2.7
Diluted	$ 1.55	$ 1.05	$ 4.17	$ 2.68
Marine Transportation [Member]
Revenues:
Revenues	$ 486,054	$ 429,885	$ 1,446,274	$ 1,269,342
Distribution and Services [Member]
Revenues:
Revenues	$ 345,095	$ 334,887	$ 1,017,287	$ 1,023,122