Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Total revenue	$ 1,876,676	$ 2,019,936	$ 5,545,797	$ 5,209,847
Operating expenses:
Salaries, wages, and benefits	726,358	710,543	2,111,143	1,780,522
Fuel	213,489	272,376	670,651	628,435
Operations and maintenance	142,418	142,913	415,302	343,604
Insurance and claims	86,510	148,865	314,394	424,210
Operating taxes and licenses	32,220	30,506	93,923	84,728
Communications	8,411	8,411	24,208	20,344
Depreciation and amortization of property and equipment	178,598	176,613	539,313	488,960
Amortization of intangibles	18,922	18,907	56,009	51,595
Rental expense	42,322	50,401	129,248	81,542
Purchased transportation	295,261	330,683	859,286	869,671
Impairments	1,008	0	10,867	0
Miscellaneous operating expenses	49,739	48,662	156,018	116,363
Total operating expenses	1,795,256	1,938,880	5,380,362	4,889,974
Operating income	81,420	81,056	165,435	319,873
Other (expenses) income:
Interest income	4,005	5,542	12,844	16,099
Interest Expense, Nonoperating	(44,398)	(39,354)	(126,116)	(86,799)
Other income, net	3,169	11,433	17,049	30,815
Total other (expenses) income, net	(37,224)	(22,379)	(96,223)	(39,885)
Income before income taxes	44,196	58,677	69,212	279,988
Income tax expense (benefit)	14,137	(1,220)	22,253	53,474
Net income	30,059	59,897	46,959	226,514
Net loss attributable to noncontrolling interest	405	297	1,170	1,290
Net income attributable to Knight-Swift	30,464	60,194	48,129	227,804
Other comprehensive income	995	152	998	1,772
Comprehensive income	$ 31,459	$ 60,346	$ 49,127	$ 229,576
Earnings per share:
Basic (in dollars per share)	$ 0.19	$ 0.37	$ 0.30	$ 1.41
Diluted (in dollars per share)	0.19	0.37	0.30	1.41
Dividends declared per share: (in dollars per share)	$ 0.16	$ 0.14	$ 0.48	$ 0.42
Weighted average shares outstanding:
Basic (in shares)	161,861	161,332	161,687	161,124
Diluted (in shares)	162,233	161,888	162,120	161,782
Revenue, excluding truckload and LTL fuel surcharge
Total revenue	$ 1,680,893	$ 1,775,249	$ 4,935,408	$ 4,615,990
Truckload and LTL fuel surcharge
Total revenue	$ 195,783	$ 244,687	$ 610,389	$ 593,857