Quarterly report pursuant to Section 13 or 15(d)

Note 15 - Stock-based Compensation (Details Textual)

v3.19.2
Note 15 - Stock-based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 3 Months Ended 4 Months Ended 5 Months Ended
Dec. 06, 2018
Apr. 30, 2019
Dec. 05, 2018
Jul. 31, 2019
Apr. 30, 2019
Apr. 30, 2019
Equivalent Vested Options Rolled Forward from Predecessor to Successor 2,783,479          
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit $ 0.87          
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit $ 6.09          
Share-based Payment Arrangement, Accelerated Cost     $ 0.6      
Selling, General and Administrative Expenses [Member]            
Share-based Payment Arrangement, Expense     $ 0.1      
Time Based Only [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   5 years        
The $13 Market/Time- Based [Member] | Closing Price of $13.00 for 30 Consecutive Days [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         3 years  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   13.00%        
The $16 Market/Time- Based [Member] | Closing Price of $16.00 for 30 Consecutive Days [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   13.00%        
The $19 Market/Time- Based [Member] | Closing Price of $19.00 for 30 Consecutive Days [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   13.00%        
The 2018 Omnibus Incentive Plan [Member]            
Share-based Payment Arrangement, Expense       $ 1.6   $ 2.0
The 2018 Omnibus Incentive Plan [Member] | UNITED KINGDOM            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance   $ 0.01     $ 0.01 $ 0.01