CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net earnings	$ 63,011		$ 57,552
Other comprehensive income (loss), net of taxes:
Pension and postretirement benefits	24		1,177
Foreign currency translation adjustments	(17)	[1]	205	[1]
Change in fair value of derivative instruments	84		974
Total comprehensive income (loss), net of taxes	91	[2]	2,356	[2]
Total comprehensive income, net of taxes	63,102		59,908
Net earnings attributable to noncontrolling interests	(765)		(974)
Comprehensive income attributable to Kirby	$ 62,337		$ 58,934

[1] Actuarial losses are amortized into costs of sales and operating expenses or selling, general and administrative expenses as appropriate. (See Note 10 – Retirement Plans)

[2] Reclassifications to net earnings of derivatives qualifying as effective hedges are recognized in interest expense or costs of sales and operating expenses as appropriate. (See Note 4 – Derivative Instruments)