CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Revenue	$ 3,265,876	$ 3,091,640	$ 2,784,754
Costs and expenses:
Costs of sales and operating expenses	2,200,354	2,180,422	2,060,941
Selling, general and administrative	337,097	335,213	302,692
Taxes, other than on income	34,910	34,766	35,071
Depreciation and amortization	240,322	211,156	201,443
Impairments	56,303	0	0
Gain on disposition of assets	(2,207)	(5,009)	(8,279)
Total costs and expenses	2,866,779	2,756,548	2,591,868
Operating income	399,097	335,092	192,886
Other income	12,795	11,041	16,677
Interest expense	(49,129)	(52,008)	(44,588)
Earnings before taxes on income	362,763	294,125	164,975
Provision for taxes on income	(75,867)	(71,220)	(42,214)
Net earnings	286,896	222,905	122,761
Less: Net (earnings) loss attributable to noncontrolling interests	(189)	30	(470)
Net earnings attributable to Kirby	$ 286,707	$ 222,935	$ 122,291
Net earnings per share attributable to Kirby common stockholders:
Basic	$ 4.95	$ 3.74	$ 2.04
Diluted	$ 4.91	$ 3.72	$ 2.03
Marine Transportation [Member]
Revenues:
Revenue	$ 1,913,050	$ 1,721,937	$ 1,616,967
Distribution and Services [Member]
Revenues:
Revenue	$ 1,352,826	$ 1,369,703	$ 1,167,787