Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Total revenue	$ 1,846,654	$ 1,552,979	$ 3,669,121	$ 3,189,911
Operating expenses:
Salaries, wages, and benefits	691,878	533,237	1,384,785	1,069,979
Fuel	222,573	168,300	457,162	356,059
Operations and maintenance	138,251	101,380	272,884	200,691
Insurance and claims	105,438	137,306	227,884	275,345
Operating taxes and licenses	30,374	28,332	61,703	54,222
Communications	8,264	6,184	15,797	11,933
Depreciation and amortization of property and equipment	178,850	156,381	360,715	312,347
Amortization of intangibles	18,544	16,505	37,087	32,688
Rental expense	43,930	16,073	86,926	31,141
Purchased transportation	286,768	258,259	564,025	538,988
Impairments	5,877	0	9,859	0
Miscellaneous operating expenses	52,447	36,992	106,279	67,701
Total operating expenses	1,783,194	1,458,949	3,585,106	2,951,094
Operating income	63,460	94,030	84,015	238,817
Other (expenses) income:
Interest income	3,817	5,508	8,839	10,557
Interest expense	(40,482)	(24,354)	(81,718)	(47,445)
Other income, net	4,888	9,679	13,880	19,382
Total other (expenses) income, net	(31,777)	(9,167)	(58,999)	(17,506)
Income before income taxes	31,683	84,863	25,016	221,311
Income tax expense	11,790	21,959	8,116	54,694
Net income	19,893	62,904	16,900	166,617
Net loss attributable to noncontrolling interest	407	422	765	993
Net income attributable to Knight-Swift	20,300	63,326	17,665	167,610
Other comprehensive income	41	531	3	1,621
Comprehensive income	$ 20,341	$ 63,857	$ 17,668	$ 169,231
Earnings per share:
Basic (in dollars per share)	$ 0.13	$ 0.39	$ 0.11	$ 1.04
Diluted (in dollars per share)	0.13	0.39	0.11	1.04
Dividends declared per share: (in dollars per share)	$ 0.16	$ 0.14	$ 0.32	$ 0.28
Weighted average shares outstanding:
Basic (in shares)	161,689	161,116	161,598	161,018
Diluted (in shares)	162,111	161,940	162,089	161,917
Revenue, excluding truckload and LTL fuel surcharge
Total revenue	$ 1,641,701	$ 1,390,448	$ 3,254,515	$ 2,840,741
Truckload and LTL fuel surcharge
Total revenue	$ 204,953	$ 162,531	$ 414,606	$ 349,170