OPERATING SEGMENT DATA - Operating Expenses by Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
OPERATING EXPENSES
Salaries, wages, and benefits	$ 436,982	$ 414,905
Rents, purchased transportation, and other costs of services	429,605	577,849
Fuel, supplies, and expenses	122,618	110,359
Depreciation and amortization	35,010	34,396
Contingent consideration	15,040	810
Other	45,680	36,829
Total consolidated operating expenses	$ 1,084,935	$ 1,175,148