Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Loss Per Share

The following table presents the components of basic and diluted earnings (loss) per share (in thousands, except per share amounts):

	Year Ended December 31,
	2023			2022			2021
Net earnings (loss) attributable to Kirby	$	222,935		$	122,291		$	(246,954	)
Undistributed earnings allocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — basic		222,873			122,258			(246,954	)
Undistributed earnings allocated to restricted shares		62			33			—
Undistributed earnings reallocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — diluted	$	222,873		$	122,258		$	(246,954	)
Shares outstanding:
Weighted average common stock issued and outstanding		59,548			60,055			60,099
Weighted average unvested restricted stock		(17	)		(17	)		(46	)
Weighted average common stock outstanding — basic		59,531			60,038			60,053
Dilutive effect of stock options and restricted stock units		326			291			—
Weighted average common stock outstanding — diluted		59,857			60,329			60,053
Net earnings (loss) per share attributable to Kirby common stockholders:
Basic	$	3.74		$	2.04		$	(4.11	)
Diluted	$	3.72		$	2.03		$	(4.11	)