Fair Value Measurement - Estimated Fair Values (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Financial Assets:
Equity method investments		$ 110,973	$ 102,252
Equity method investments (Estimated Fair Value)		110,973	102,252
Financial Liabilities:
Term loan Carrying Value		1,744,450	1,628,079
Revolving line of credit		202,000	67,000
Secured Debt	[1],[2]	269,303	279,339
Accounts receivable securitization		453,567	526,508
Business Combination, Contingent Consideration, Liability	[3]	40,859	40,859
2023 Term Loan
Financial Liabilities:
Deferred loan costs		800	900
2023 Term Loan | Loans Payable [Member]
Financial Liabilities:
Deferred loan costs		800	900
U.S. Xpress | Class A
Financial Liabilities:
Business Combination, Contingent Consideration, Liability	[3]	134,107	134,107
2021 Term Loan A-2
Financial Liabilities:
Term loan Carrying Value	[4]	199,939	199,902
Term loan, Fair Value	[4]	200,000	200,000
2021 Term Loan A-3
Financial Liabilities:
Term loan Carrying Value	[4]	799,147	799,058
Term loan, Fair Value	[4]	800,000	800,000
2023 Term Loan
Financial Liabilities:
Term loan Carrying Value	[5]	249,216	249,135
Term loan, Fair Value	[5]	250,000	250,000
2021 Revolver
Financial Liabilities:
Revolving line of credit		202,000	67,000
U.S. Xpress Revenue Equipment Installment Notes
Financial Liabilities:
Secured Debt	[6]	269,303	279,339
Debt Instrument, Fair Value Disclosure		1,100	1,300
2021 Prudential Notes
Financial Liabilities:
Term loan Carrying Value	[7]	17,035	25,078
Term loan, Fair Value	[7]	17,054	25,100
Debt Instrument, Fair Value Disclosure		1,000	1,100
Deferred loan costs		19	22
2023 RSA
Financial Liabilities:
Accounts receivable securitization	[8]	453,567	526,508
Debt Instrument, Fair Value Disclosure	[8]	454,000	527,000
Deferred loan costs		$ 400	$ 500

[1] Refer to Note 12 for information regarding the fair value of debt.

[2] The revenue equipment installment loans were assumed at the close of the U.S. Xpress Acquisition and have a weighted average interest rate of 5.83% and 4.70% as of March 31, 2024 and December 31, 2023, respectively.

[3] he contingent consideration is primarily related to the U.S. Xpress Acquisition

[4] As of March 31, 2024, the carrying amounts of the 2021 Term Loan A-2 and 2021 Term Loan A-3 were net of $0.1 million and $0.9 million in deferred loan costs, respectively. As of December 31, 2023, the carrying amounts of the 2021 Term Loan A-2 and 2021 Term Loan A-3 were net of $0.1 million and $0.9 million in deferred loan costs, respectively.

[5] As of March 31, 2024, the carrying amount of the 2023 Term Loan was net of $0.8 million in deferred loan costs. As of December 31, 2023, the carrying amount of the 2023 Term Loan was net of $0.9 million in deferred loan costs.

[6] As of March 31, 2024, the carrying amount of the revenue equipment installment notes included $1.1 million in fair value adjustments. As of December 31, 2023, the carrying amount of the revenue equipment installment notes included $1.3 million in fair value adjustments.

[7] As of March 31, 2024, the carrying amount of the 2021 Prudential Notes was net of approximately $19,000 in deferred loan costs and included $1.0 million in fair value adjustments. As of December 31, 2023, the carrying amount of the 2021 Prudential Notes was net of $22,000 in deferred loan costs and included $1.1 million in fair value adjustments.

[8] The carrying amount of the 2023 RSA was net of $0.4 million and $0.5 million in deferred loan costs as of March 31, 2024 and December 31, 2023, respectively.