Condensed Consolidated Balance Sheets (Unaudited) - USD ($) shares in Thousands, $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents		$ 204,762	$ 168,545
Cash and cash equivalents – restricted	[1]	136,174	297,275
Restricted investments, held-to-maturity, amortized cost		0	530
Trade receivables, net of allowance for doubtful accounts of $40,739 and $39,458, respectively		867,610	888,603
Contract balance – revenue in transit		13,622	12,246
Prepaid expenses		137,105	148,696
Assets held for sale		78,918	83,366
Income tax receivable		58,273	65,815
Other current assets		35,707	43,939
Total current assets		1,532,171	1,709,015
Gross property and equipment		6,782,857	6,720,610
Less: accumulated depreciation and amortization		(2,205,709)	(2,104,211)
Property and equipment, net		4,577,148	4,616,399
Operating lease right-of-use-assets		443,002	484,821
Goodwill		3,873,131	3,848,798
Intangible assets, net		2,040,339	2,058,882
Other long-term assets		163,079	152,850
Total assets		12,628,870	12,870,765
Current liabilities:
Accounts payable		283,837	355,173
Accrued payroll and purchased transportation		153,996	164,884
Accrued liabilities		224,749	220,350
Claims accruals – current portion		350,030	480,200
Finance lease liabilities and long-term debt – current portion		505,841	459,759
Operating lease liabilities – current portion		124,840	144,921
Total current liabilities		1,643,293	1,825,287
Revolving line of credit		202,000	67,000
Long-term debt – less current portion		1,193,602	1,223,021
Finance lease liabilities – less current portion		375,666	407,150
Operating lease liabilities – less current portion		342,320	371,407
Accounts receivable securitization		453,567	526,508
Claims accruals – less current portion		303,743	315,476
Deferred tax liabilities		930,629	951,749
Other long-term liabilities		111,828	79,086
Total liabilities		5,556,648	5,766,684
Commitments and contingencies (Notes 7, 8, and 9)
Stockholders’ equity:
Preferred stock, par value $0.01 per share; 10,000 shares authorized; none issued		$ 0	$ 0
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)		10,000	10,000
Preferred stock, shares issued (in shares)		0	0
Common stock, par value $0.01 per share; 500,000 shares authorized; 161,593 and 161,385 shares issued and outstanding as of March 31, 2024 and December 31, 2023, respectively.		$ 1,616	$ 1,613
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		500,000	500,000
Common stock, shares issued (in shares)		161,593	161,385
Common stock, shares outstanding (in shares)		161,593	161,385
Additional paid-in capital		$ 4,430,736	$ 4,426,852
Accumulated other comprehensive loss		(868)	(830)
Retained earnings		2,624,666	2,659,755
Total Knight-Swift stockholders' equity		7,056,150	7,087,390
Noncontrolling interest		16,072	16,691
Total stockholders’ equity		7,072,222	7,104,081
Total liabilities and stockholders’ equity		$ 12,628,870	$ 12,870,765
Common Class A [Member]
Stockholders’ equity:
Common stock, shares outstanding (in shares)		161,593	161,385

[1] Reflects cash and cash equivalents that are primarily restricted for claims payments.