Earnings Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Earnings Per Share

(10) Earnings 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	)

Diluted earnings per share was computed using the treasury stock method. Certain outstanding options to purchase approximately 33,000, 381,000, and 567,000 shares of common stock were excluded in the computation of diluted earnings per share as of December 31, 2023, 2022, and 2021, respectively, as such stock options would have been antidilutive. Certain outstanding RSUs to convert to 7,000 shares of common stock were also excluded in the computation of diluted earnings per share as of December 31, 2021 as such RSUs would have been antidilutive. No RSUs were antidilutive at December 31, 2023 and 2022.