CONDENSED STATEMENTS OF EARNINGS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Marine transportation	$ 418,518	$ 335,957
Diesel engine services	140,267	230,978
Total revenues	558,785	566,935
Costs and expenses:
Costs of sales and operating expenses	369,274	384,359
Selling, general and administrative	44,156	53,100
Taxes, other than on income	4,478	3,914
Depreciation and amortization	40,996	36,474
Loss on disposition of assets	32	28
Total costs and expenses	458,936	477,875
Operating income	99,849	89,060
Other income	75	149
Interest expense	(7,988)	(5,840)
Earnings before taxes on income	91,936	83,369
Provision for taxes on income	(34,384)	(31,490)
Net earnings	57,552	51,879
Less: Net earnings attributable to noncontrolling interests	(974)	(935)
Net earnings attributable to Kirby	$ 56,578	$ 50,944
Net earnings per share attributable to Kirby common stockholders:
Basic (in dollars per share)	$ 1.00	$ 0.91
Diluted (in dollars per share)	$ 1.00	$ 0.91