CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets, Current [Abstract]
Cash and cash equivalents	$ 36,991	$ 34,813
Accounts receivable:
Trade - less allowance for doubtful accounts	482,744	417,958
Other	133,278	149,964
Inventories - net	392,470	331,350
Prepaid expense and other current assets	80,899	69,780
Total current assets	1,126,382	1,003,865
Property and equipment	5,434,740	5,392,851
Accumulated depreciation	(1,794,050)	(1,714,336)
Property and equipment - net	3,640,690	3,678,515
Operating lease right-of-use assets	153,723	167,730
Goodwill	438,748	438,748
Other intangibles, net	53,615	60,070
Other assets	43,140	50,135
Total assets	5,456,298	5,399,063
Current liabilities:
Bank notes payable	3,599	1,934
Accounts payable	241,623	199,088
Accrued liabilities	209,724	236,078
Current portion of operating lease liabilities	33,495	33,902
Deferred revenues	82,120	72,770
Total current liabilities	570,561	543,772
Long-term debt, net - less current portion	1,114,860	1,161,433
Deferred income taxes	604,596	574,152
Operating lease liabilities - less current portion	144,201	159,672
Other long-term liabilities	46,717	71,252
Total long-term liabilities	1,910,374	1,966,509
Contingencies and commitments	0	0
Kirby stockholders' equity:
Common stock, $0.10 par value per share. Authorized 120 million shares, issued 65.5 million shares	6,547	6,547
Additional Paid in Capital	857,674	854,512
Accumulated other comprehensive income - net	(13,455)	(25,966)
Retained earnings	2,431,421	2,346,439
Treasury stock - at cost, 5.5 million shares at September 30, 2022 and 5.4 million at December 31, 2021	(309,130)	(295,208)
Total Kirby stockholders' equity	2,973,057	2,886,324
Noncontrolling interests	2,306	2,458
Total equity	2,975,363	2,888,782
Total liabilities and equity	$ 5,456,298	$ 5,399,063