CONDENSED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 5,263	$ 11,059
Accounts receivable:
Trade - less allowance for doubtful accounts	331,131	313,182
Other	46,489	43,074
Inventories - net	139,547	177,397
Prepaid expenses and other current assets	38,277	39,248
Deferred income taxes	6,464	12,296
Total current assets	567,171	596,256
Property and equipment	3,332,462	3,219,113
Less accumulated depreciation	(948,499)	(903,948)
Property and equipment - net	2,383,963	2,315,165
Goodwill	599,001	596,030
Other assets	174,174	145,677
Total assets	3,724,309	3,653,128
Current liabilities:
Current portion of long-term debt	78,000	65,000
Income taxes payable	4,107	2,369
Accounts payable	165,502	156,763
Accrued liabilities	121,973	114,031
Deferred revenues	31,506	16,857
Total current liabilities	401,088	355,020
Long-term debt - less current portion	943,240	1,070,110
Deferred income taxes	467,885	426,096
Other long-term liabilities	75,936	94,848
Total long-term liabilities	1,487,061	1,591,054
Contingencies and commitments
Kirby stockholders' equity:
Common stock, $.10 par value per share. Authorized 120,000,000 shares, issued 59,776,000 shares	5,978	5,978
Additional paid-in capital	401,826	397,785
Accumulated other comprehensive income - net	(58,237)	(61,127)
Retained earnings	1,558,750	1,439,079
Treasury stock - at cost, 3,021,000 at June 30, 2013 and 3,191,000 at December 31, 2012	(83,596)	(86,747)
Total Kirby stockholders' equity	1,824,721	1,694,968
Noncontrolling interests	11,439	12,086
Total equity	1,836,160	1,707,054
Total liabilities and equity	$ 3,724,309	$ 3,653,128