CONDENSED STATEMENTS OF EARNINGS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues	$ 771,042	$ 802,671	$ 1,515,663	$ 1,544,359
Costs and expenses:
Costs of sales and operating expenses	563,495	588,628	1,100,150	1,141,945
Selling, general and administrative	69,150	92,588	141,946	169,384
Taxes, other than on income	10,579	10,552	20,577	19,087
Depreciation and amortization	55,093	55,492	110,316	109,710
Gain on disposition of assets	(3,118)	(442)	(5,275)	(2,340)
Total costs and expenses	695,199	746,818	1,367,714	1,437,786
Operating income	75,843	55,853	147,949	106,573
Other income	2,381	1,541	1,813	3,132
Interest expense	(15,515)	(12,540)	(28,716)	(22,320)
Earnings before taxes on income	62,709	44,854	121,046	87,385
Provision for taxes on income	(15,269)	(16,061)	(29,149)	(25,926)
Net earnings	47,440	28,793	91,897	61,459
Less: Net earnings attributable to noncontrolling interests	(153)	(191)	(314)	(386)
Net earnings attributable to Kirby	$ 47,287	$ 28,602	$ 91,583	$ 61,073
Net earnings per share attributable to Kirby common stockholders:
Basic (in dollars per share)	$ 0.79	$ 0.48	$ 1.53	$ 1.02
Diluted (in dollars per share)	$ 0.79	$ 0.48	$ 1.53	$ 1.02
Marine Transportation [Member]
Revenues:
Total revenues	$ 404,286	$ 378,163	$ 772,407	$ 718,566
Distribution and Services [Member]
Revenues:
Total revenues	$ 366,756	$ 424,508	$ 743,256	$ 825,793