Quarterly report pursuant to Section 13 or 15(d)

Note 8 - Goodwill and Intangible Assets (Details Textual)

v3.20.2
Note 8 - Goodwill and Intangible Assets (Details Textual) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended 8 Months Ended 9 Months Ended
Dec. 05, 2018
Jul. 31, 2020
Apr. 30, 2020
Jul. 31, 2019
Apr. 30, 2020
Jul. 31, 2019
Jul. 31, 2020
Goodwill, Impairment Loss             $ 52,944
Amortization of Intangible Assets, Total $ 700 $ 8,100   $ 10,400   $ 22,235 $ 25,290
US Concrete Pumping [Member]              
Reporting Unit, Percentage of Carrying Amount In Excess of Fair Value     6.90%   6.90%    
Goodwill, Impairment Loss     $ 38,500   $ 38,500    
UK Operations [Member]              
Reporting Unit, Percentage of Carrying Amount In Excess of Fair Value     14.80%   14.80%    
Goodwill, Impairment Loss     $ 14,400   $ 14,400    
US Concrete Waste Management Services [Member]              
Reporting Unit, Percentage of Carrying Amount In Excess of Fair Value     4.50%   4.50%    
Goodwill, Impairment Loss     $ 0   $ 0    
Brundage-Bone Concrete Pumping, Trade Name [Member]              
Indefinite-lived Intangible Assets, Carrying Value in Excess of Fair Value, Percent     11.80%   11.80%    
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)     $ 5,000   $ 5,000    
Indefinite-Lived Trade Names     $ 37,300   $ 37,300    
Eco-Pan, Trade Name [Member]              
Indefinite-lived Intangible Assets, Carrying Value in Excess of Fair Value, Percent     7.80%   7.80%    
Indefinite-Lived Trade Names     $ 7,700   $ 7,700    
Capital Pumping, Trade Name [Member]              
Indefinite-lived Intangible Assets, Carrying Value in Excess of Fair Value, Percent     109.10%   109.10%    
Indefinite-Lived Trade Names     $ 5,500   $ 5,500