Long-term Debt (Tables)

9 Months Ended

Sep. 30, 2019

Debt Disclosure [Abstract]

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

	September 30, 2019		December 31, 2018
Line of credit, maturing June 2023	$	2,900	$	—
Term loan agreement, interest rate of 4.3% and 4.8% at September 30, 2019 and December 31, 2018, respectively, maturing June 2023		187,500		195,000
Revenue equipment installment notes with finance  companies, weighted average interest rate of 4.7% and 5.0% at September 30, 2019 and December 31, 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 $225.0 million and $197.1 million at September 30, 2019 and December 31, 2018		210,666		184,867
Mortgage note payables, interest rates ranging from 6.26% to 6.99% at September 30, 2019 and December 31, 2018 due in monthly installments with final maturities at various dates through September 2031, secured by real estate with a net book value of $20.5 million and $24.1 million at September 30, 2019 and December 31, 2018		18,041		18,861
Other		408		6,872
		419,515		405,600
Less: Debt issuance costs		(1,301)		(1,347)
Less: Current maturities of long-term debt		(75,269)		(106,383)
	$	342,945	$	297,870