Note 12 - Goodwill and Other Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill, Impairment Loss		$ 0
Acquired Finite-lived Intangible Asset, Residual Value		0
Amortization of Intangible Assets		4,200	$ 1,000	$ 1,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		8,600
Finite-Lived Intangible Assets, Amortization Expense, Year Two		7,800
Finite-Lived Intangible Assets, Amortization Expense, Year Three		7,600
Finite-Lived Intangible Assets, Amortization Expense, Year Four		7,600
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 7,600
Special Logistics Dedicated, LLC [Member]
Goodwill, Acquired During Period	$ 40,000
Finite-lived Intangible Assets Acquired	$ 76,000