CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]	Total
Balance at beginning of year at Dec. 31, 2011	$ 5,928,000	$ 357,294,000	$ (56,176,000)	$ 1,229,641,000	$ (94,162,000)	$ 11,633,000
Issuance of shares in acquisition	50,000	29,030,000
Excess of proceeds received upon exercise of stock options and issuance of restricted stock over cost of treasury stock issued		6,716,000
Tax benefit realized from equity compensation plans		3,212,000					3,212,000
Issuance of restricted stock, net of forfeitures		(8,263,000)
Amortization of unearned compensation		9,796,000
Net earnings attributable to Kirby for the year				209,438,000			209,438,000
Purchase of treasury stock (187,000 in 2014)					0
Cost of treasury stock issued upon exercise of stock options and issuance of restricted stock (211,000 in 2014, 261,000 in 2013 and 341,000 in 2012)					7,415,000
Net earnings attributable to noncontrolling interests						3,181,000	(3,181,000)
Return of investment to noncontrolling interests						(2,728,000)	2,728,000
Other comprehensive income (loss), net of taxes			(4,951,000)				(4,951,000)	[1]
Balance at end of year at Dec. 31, 2012	5,978,000	397,785,000	(61,127,000)	1,439,079,000	(86,747,000)	12,086,000
Issuance of shares in acquisition	0	0
Excess of proceeds received upon exercise of stock options and issuance of restricted stock over cost of treasury stock issued		8,276,000
Tax benefit realized from equity compensation plans		3,001,000					3,001,000
Issuance of restricted stock, net of forfeitures		(10,068,000)
Amortization of unearned compensation		11,621,000
Net earnings attributable to Kirby for the year				253,061,000			253,061,000
Purchase of treasury stock (187,000 in 2014)					0
Cost of treasury stock issued upon exercise of stock options and issuance of restricted stock (211,000 in 2014, 261,000 in 2013 and 341,000 in 2012)					5,493,000
Net earnings attributable to noncontrolling interests						3,238,000	(3,238,000)
Return of investment to noncontrolling interests						(3,857,000)	3,857,000
Other comprehensive income (loss), net of taxes			44,334,000				44,334,000	[1]
Balance at end of year at Dec. 31, 2013	5,978,000	410,615,000	(16,793,000)	1,692,140,000	(81,254,000)	11,467,000	2,022,153,000
Issuance of shares in acquisition	0	0
Excess of proceeds received upon exercise of stock options and issuance of restricted stock over cost of treasury stock issued		8,345,000
Tax benefit realized from equity compensation plans		6,119,000					6,119,000
Issuance of restricted stock, net of forfeitures		(8,195,000)
Amortization of unearned compensation		11,591,000
Net earnings attributable to Kirby for the year				282,006,000			282,006,000
Purchase of treasury stock (187,000 in 2014)					(15,321,000)
Cost of treasury stock issued upon exercise of stock options and issuance of restricted stock (211,000 in 2014, 261,000 in 2013 and 341,000 in 2012)					3,049,000
Net earnings attributable to noncontrolling interests						2,602,000	(2,602,000)
Return of investment to noncontrolling interests						(3,192,000)	3,192,000
Other comprehensive income (loss), net of taxes			(44,244,000)				(44,244,000)	[1]
Balance at end of year at Dec. 31, 2014	$ 5,978,000	$ 428,475,000	$ (61,037,000)	$ 1,974,146,000	$ (93,526,000)	$ 10,877,000	$ 2,264,913,000

[1] (b) 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)