Summary of Significant Accounting Policies - Schedule of Measure of Segment Assets (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenues		$ 817,115	$ 823,244	$ 1,604,690	$ 1,578,019
Wages	[1]	231,441	227,223	464,969	434,649
Salaries	[1]	50,150	46,584	101,826	91,783
Purchased Transportation		57,699	61,047	117,548	113,554
Other Segment items	[2]	315,007	297,935	628,675	580,029
Depreciation and amortization		62,546	52,536	121,589	101,385
Interest Expense		4,742	2,412	9,027	2,954
Interest Income		(34)	(110)	(73)	(865)
Income Tax Expense		24,173	33,098	39,928	61,316
Segment and Consolidated Net Income		$ 71,391	$ 102,519	$ 121,201	$ 193,214

[1] Wages includes payroll costs for non-management employees generally paid on an hourly or per-mile basis. Salaries includes payroll costs for exempt employees.

[2] Other segment items include employees' benefits, fuel, operating expenses and supplies, operating taxes and licenses and claims and insurance.