| Share-based Payment Arrangement, Activity [Table Text Block] |
| Location |
|
Type of Award |
|
Shares Unvested at April 30, 2021 |
|
|
Weighted Average Fair Value |
|
|
Unrecognized Compensation Expense at April 30, 2021 |
|
Date Expense will be Recognized Through (Straight-Line Basis) |
| U.S. |
|
Time Based Only |
|
|
864,028 |
|
|
$ |
6.20 |
|
|
$ |
3,894,504 |
|
12/6/2023 |
| U.S. |
|
$6 Market/Time- Based |
|
|
150,697 |
|
|
$ |
3.86 |
|
|
$ |
- |
|
10/29/2020 |
| U.S. |
|
$6 Market/Time- Based |
|
|
192,652 |
|
|
$ |
8.63 |
|
|
$ |
535,622 |
|
3/29/2022 |
| U.S. |
|
$6 Market/Time- Based |
|
|
192,652 |
|
|
$ |
8.63 |
|
|
$ |
818,896 |
|
3/29/2023 |
| U.S. |
|
$6 Market/Time- Based |
|
|
192,663 |
|
|
$ |
8.63 |
|
|
$ |
987,767 |
|
3/29/2024 |
| U.S. |
|
$8 Market/Time- Based |
|
|
150,697 |
|
|
$ |
3.46 |
|
|
$ |
- |
|
10/29/2020 |
| U.S. |
|
$8 Market/Time- Based |
|
|
192,653 |
|
|
$ |
7.43 |
|
|
$ |
623,894 |
|
5/1/2023 |
| U.S. |
|
$8 Market/Time- Based |
|
|
192,653 |
|
|
$ |
7.43 |
|
|
$ |
795,783 |
|
5/1/2024 |
| U.S. |
|
$8 Market/Time- Based |
|
|
192,662 |
|
|
$ |
7.43 |
|
|
$ |
908,426 |
|
5/1/2025 |
| U.S. |
|
$10 Market/Time- Based |
|
|
150,706 |
|
|
$ |
3.15 |
|
|
$ |
- |
|
10/29/2020 |
| U.S. |
|
$10 Market/Time- Based |
|
|
192,658 |
|
|
$ |
6.45 |
|
|
$ |
580,256 |
|
7/9/2023 |
| U.S. |
|
$10 Market/Time- Based |
|
|
192,654 |
|
|
$ |
6.45 |
|
|
$ |
715,214 |
|
7/9/2024 |
| U.S. |
|
$10 Market/Time- Based |
|
|
192,670 |
|
|
$ |
6.45 |
|
|
$ |
805,215 |
|
7/9/2025 |
| U.S. |
|
$13 Market/Time- Based |
|
|
433 |
|
|
$ |
4.47 |
|
|
$ |
794 |
|
5/4/2022 |
| U.S. |
|
$13 Market/Time- Based |
|
|
433 |
|
|
$ |
4.47 |
|
|
$ |
1,045 |
|
5/4/2023 |
| U.S. |
|
$13 Market/Time- Based |
|
|
434 |
|
|
$ |
4.47 |
|
|
$ |
1,209 |
|
5/4/2024 |
| U.S. |
|
$16 Market/Time- Based |
|
|
433 |
|
|
$ |
3.85 |
|
|
$ |
764 |
|
8/27/2022 |
| U.S. |
|
$16 Market/Time- Based |
|
|
433 |
|
|
$ |
3.85 |
|
|
$ |
950 |
|
8/27/2023 |
| U.S. |
|
$16 Market/Time- Based |
|
|
434 |
|
|
$ |
3.85 |
|
|
$ |
1,076 |
|
8/27/2024 |
| U.S. |
|
$19 Market/Time- Based |
|
|
433 |
|
|
$ |
3.34 |
|
|
$ |
708 |
|
11/19/2022 |
| U.S. |
|
$19 Market/Time- Based |
|
|
433 |
|
|
$ |
3.34 |
|
|
$ |
853 |
|
11/19/2023 |
| U.S. |
|
$19 Market/Time- Based |
|
|
434 |
|
|
$ |
3.34 |
|
|
$ |
953 |
|
11/19/2024 |
| U.K. |
|
Time Based Only |
|
|
132,259 |
|
|
$ |
6.08 |
|
|
$ |
550,704 |
|
12/6/2023 |
| U.K. |
|
$6 Market/Time- Based |
|
|
28,885 |
|
|
$ |
3.85 |
|
|
$ |
- |
|
10/29/2020 |
| U.K. |
|
$6 Market/Time- Based |
|
|
27,892 |
|
|
$ |
8.36 |
|
|
$ |
76,663 |
|
3/29/2022 |
| U.K. |
|
$6 Market/Time- Based |
|
|
27,892 |
|
|
$ |
8.36 |
|
|
$ |
116,244 |
|
3/29/2023 |
| U.K. |
|
$6 Market/Time- Based |
|
|
27,901 |
|
|
$ |
8.36 |
|
|
$ |
139,791 |
|
3/29/2024 |
| U.K. |
|
$8 Market/Time- Based |
|
|
28,885 |
|
|
$ |
3.45 |
|
|
$ |
- |
|
10/29/2020 |
| U.K. |
|
$8 Market/Time- Based |
|
|
27,892 |
|
|
$ |
7.20 |
|
|
$ |
88,882 |
|
5/1/2023 |
| U.K. |
|
$8 Market/Time- Based |
|
|
27,892 |
|
|
$ |
7.20 |
|
|
$ |
112,737 |
|
5/1/2024 |
| U.K. |
|
$8 Market/Time- Based |
|
|
27,901 |
|
|
$ |
7.20 |
|
|
$ |
128,403 |
|
5/1/2025 |
| U.K. |
|
$10 Market/Time- Based |
|
|
28,886 |
|
|
$ |
3.14 |
|
|
$ |
- |
|
10/29/2020 |
| U.K. |
|
$10 Market/Time- Based |
|
|
27,902 |
|
|
$ |
6.24 |
|
|
$ |
82,553 |
|
7/9/2023 |
| U.K. |
|
$10 Market/Time- Based |
|
|
27,892 |
|
|
$ |
6.24 |
|
|
$ |
101,225 |
|
7/9/2024 |
| U.K. |
|
$10 Market/Time- Based |
|
|
27,901 |
|
|
$ |
6.24 |
|
|
$ |
113,743 |
|
7/9/2025 |
| Total |
|
|
3,523,925 |
|
|
|
|
|
|
$ |
12,184,873 |
|
|
|