Long-term Debt (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

	December 31, 2019		December 31, 2018
Line of credit, maturing June 2023	$	—	$	—
Term loan agreement, interest rate of 4.3% and 4.8% at December 31, 2019 and December 31, 2018, respectively, maturing June 2023		150,000		195,000
Revenue equipment installment notes with finance  companies, weighted average interest rate of 4.7% and 5.0% at December 31, 2019 and 2018, due in monthly installments with final maturities at various dates through February 2026, secured by related revenue equipment with a net book value of $220.4 million and $197.1 million at December 31, 2019 and 2018		208,252		184,867
Mortgage note payables, interest rates ranging from 6.26% to 6.99% at December 31, 2019 and 2018 due in monthly installments with final maturities at various dates through September 2031, secured by real estate with a net book value of $20.2 million and $24.1 million at December 31, 2019 and 2018		17,776		18,861
Other		8,795		6,872
		384,823		405,600
Less: Debt issuance costs		(1,223)		(1,347)
Less: Current maturities of long-term debt		(75,596)		(106,383)
	$	308,004	$	297,870

Schedule of Maturities of Long-term Debt [Table Text Block]

2020	$	75,596
2021		42,602
2022		61,874
2023		179,403
2024		3,904
Thereafter		21,444
	$	384,823