Quarterly report pursuant to Section 13 or 15(d)

Note 15 - Stock-based Compensation (Details Textual)

v3.20.1
Note 15 - Stock-based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 3 Months Ended 5 Months Ended 6 Months Ended 11 Months Ended 12 Months Ended
Dec. 05, 2018
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2019
Apr. 30, 2020
Oct. 31, 2019
Oct. 31, 2019
Equivalent Vested Options Rolled Forward from Predecessor to Successor (in shares)           2,783,479  
Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit (in dollars per share)           $ 0.87  
Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit (in dollars per share)           6.09  
Share-based Payment Arrangement, Accelerated Cost $ 0.6            
Time Based Only [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)             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 (Year)             3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage             33.30%
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 (Year)             3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage             33.30%
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 (Year)             3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage             33.30%
The 2018 Omnibus Incentive Plan [Member]              
Share-based Payment Arrangement, Expense $ 0.1 $ 1.4 $ 0.4 $ 0.4 $ 2.9    
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 (in dollars per share)           $ 0.01 $ 0.01