Long-term Debt (Tables)

3 Months Ended

Mar. 31, 2020

Debt Disclosure [Abstract]

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

	March 31, 2020		December 31, 2019
Line of credit, maturing January 2025	$	77,000	$	—
Term loan agreement, interest rate of 4.3% at December 31, 2019, terminated January 2020		—		150,000
Revenue equipment installment notes with finance  companies, weighted average interest rate of 4.4% and 4.7% at March 31, 2020 and December 31, 2019, due in monthly installments with final maturities at various dates through March 2027, secured by related revenue equipment with a net book value of $328.3 million and $220.4 million at March 31, 2020 and December 31, 2019		326,186		208,252
Mortgage note payables, interest rates ranging from 4.17% to 6.99% at March 31, 2020 and December 31, 2019 due in monthly installments with final maturities at various dates through September 2031, secured by real estate with a net book value of $30.5 million and $20.2 million at March 31, 2020 and December 31, 2019		26,964		17,776
Other		5,868		8,795
		436,018		384,823
Less: Debt issuance costs		(324)		(1,223)
Less: Current maturities of long-term debt		(79,396)		(75,596)
	$	356,298	$	308,004