Acquisitions (Details) (USD $)	12 Months Ended			0 Months Ended			0 Months Ended				0 Months Ended						0 Months Ended	3 Months Ended		0 Months Ended		0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 28, 2012 Flag Service & Maintenance, Inc. [Member]	Dec. 14, 2012 Penn Maritime Inc. and Maritime Investments LLC [Member] TankBarge bbl	Dec. 14, 2012 Penn Maritime Inc. and Maritime Investments LLC [Member] Tugboats [Member] ProductiveAsset	Jul. 02, 2011 K-Sea Transportation Partners L.P. [Member] bbl TankBarge	Jun. 28, 2011 K-Sea Transportation Partners L.P. [Member]	Jun. 28, 2011 K-Sea Transportation Partners L.P. [Member] Tank Barges [Member] ProductiveAsset	Jun. 28, 2011 K-Sea Transportation Partners L.P. [Member] Tugboats [Member] ProductiveAsset	Apr. 15, 2011 United Holdings LLC [Member] Location State	Dec. 15, 2011 Seaboats, Inc. [Member]	Dec. 15, 2011 Seaboats, Inc. [Member] Tank Barges [Member] bbl ProductiveAsset	Feb. 24, 2011 Enterprise Marine Services LLC [Member]	Feb. 24, 2011 Enterprise Marine Services LLC [Member] Tank Barges [Member] ProductiveAsset	Feb. 24, 2011 Enterprise Marine Services LLC [Member] Towboat [Member] ProductiveAsset	Nov. 01, 2012 Allied Transportation Company [Member] bbl	Mar. 31, 2013 Allied Transportation Company [Member]	Nov. 01, 2012 Allied Transportation Company [Member] Tank Barges [Member] ProductiveAsset	Nov. 01, 2012 Allied Transportation Company [Member] Offshore Dry Bulk Barges [Member] T ProductiveAsset	Nov. 01, 2012 Allied Transportation Company [Member] Coastal Tugboats [Member] ProductiveAsset	Feb. 09, 2011 Kinder Morgan Petcoke, L.P. [Member]
Business acquisition, consideration transferred [Abstract]
Cash consideration paid				$ 6,864,000	$ 146,750,000			$ 227,617,000			$ 271,192,000	$ 42,745,000		$ 53,200,000			$ 108,547,000					$ 4,050,000
Total value of transaction					300,538,000			603,427,000
Stock consideration through issuance of Company common stock					29,080,000			113,019,000
Issue of common stock (in shares)					500,000		1,939,234
Shares issued per share (in dollars per share)					$ 58.16			$ 58.28
Number of doubled hulled tank barges					18		54
Capacity, in barrels, of purchased productive assets (in barrels)					1,900,000		3,800,000						80,000				680,000
Number of productive assets purchased						16			57	63			3		21	15			10	3	7
Useful life of purchased productive assets							9 years
Weighted average amortization period												5 years
Cash to retire outstanding debt					124,708,000			262,791,000
Capacity, in deadweight tons of purchased productive assets																				48,000
Acquisition and integration related costs																	10,000,000
Fair value of contingent earnout provision payable in 2014																	9,756,000
Earnout provisional for payment to additional payables											50,000,000
Number of operational locations											21
Number of operational states											7
Percentage of ownership acquired (in hundredths)																						51.00%
Noncontrolling interest attributable to parent (in hundredths)																						49.00%
Purchase price of towboat																						1,250,000
Payment of contingent liability	(5,000,000)	0	0															5,000,000
Earnout provision period											3 years
Entity's pro forma revenues [Abstract]
Revenues	2,242,195,000	2,112,658,000	2,105,904,000
Net earnings attributable to Kirby	$ 253,061,000	$ 209,438,000	$ 172,426,000
Net earnings per share attributable to Kirby common stockholders [Abstract]
Basic (in dollars per share)	$ 4.46	$ 3.75	$ 3.10
Diluted (in dollars per share)	$ 4.44	$ 3.73	$ 3.09