Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating revenues		$ 12,087,204	$ 12,829,665	$ 14,813,999
Operating expenses:
Rents and purchased transportation		5,378,336	5,872,591	7,392,179
Salaries, wages and employee benefits		3,232,440	3,257,484	3,373,063
Depreciation and amortization		761,141	737,954	644,520
Fuel and fuel taxes		652,129	751,497	931,710
Operating supplies and expenses		495,375	509,354	502,553
Insurance and claims		313,664	315,678	318,123
General and administrative expenses, net of asset dispositions		306,355	274,564	215,361
Operating taxes and licenses		72,547	74,996	68,230
Communication and utilities		43,992	42,351	36,707
Total operating expenses		11,255,979	11,836,469	13,482,446
Operating income	[1]	831,225	993,196	1,331,553
Interest income		7,311	7,624	1,069
Interest expense		79,020	65,933	51,249
Earnings before income taxes		759,516	934,887	1,281,373
Income taxes		188,630	206,600	312,022
Net earnings		$ 570,886	$ 728,287	$ 969,351
Weighted average basic shares outstanding (in shares)		101,947	103,440	104,141
Basic earnings per share (in dollars per share)		$ 5.6	$ 7.04	$ 9.31
Weighted average diluted shares outstanding (in shares)		102,754	104,451	105,276
Diluted earnings per share (in dollars per share)		$ 5.56	$ 6.97	$ 9.21
Service Excluding Fuel Surcharge [Member]
Operating revenues		$ 10,557,709	$ 10,978,387	$ 12,381,359
Fuel Surcharge [Member]
Operating revenues		$ 1,529,495	$ 1,851,278	$ 2,432,640

[1] Refer to the Consolidated Statements of Earnings for the reconciliation of consolidated operating income to earnings before income taxes.