CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 17,586	$ (3,120)
Other comprehensive income (loss), net of taxes:
Pension and postretirement benefits	13	745
Foreign currency translation adjustments	476	(497)
Total other comprehensive income (loss), net of taxes	489	248
Total comprehensive income (loss), net of taxes	18,075	(2,872)
Net earnings attributable to noncontrolling interests	(152)	(255)
Comprehensive income (loss) attributable to Kirby	$ 17,923	$ (3,127)