Note 2 - Stock Based Compensation (Tables)
|
12 Months Ended |
Sep. 30, 2023 |
|---|
| Notes Tables |
|
| Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| |
|
Year ended September 30, 2023
|
|
|
Year ended September 30, 2022
|
|
|
Year ended September 30, 2021
|
|
|
Dividend yield
|
|
|
0 |
% |
|
|
0 |
% |
|
|
0 |
% |
|
Weighted average expected volatility
|
|
|
63.14 |
% |
|
|
52.02 |
% |
|
|
46.90 |
% |
|
Weighted average risk-free interest rate
|
|
|
3.75 |
% |
|
|
0.97 |
% |
|
|
0.24 |
% |
|
Weighted average expected life
|
|
5 years
|
|
|
5 years
|
|
|
5 years
|
|
|
Vesting period
|
|
3 years
|
|
|
3 years
|
|
|
3 years
|
|
|
| Share-Based Payment Arrangement, Option, Activity [Table Text Block] |
| |
|
Number of shares
|
|
|
Weighted average exercise price
|
|
|
Weighted average fair value
|
|
|
Outstanding as of September 30, 2020
|
|
|
337,100 |
|
|
$ |
12.48 |
|
|
|
|
|
|
Granted
|
|
|
105,089 |
|
|
|
23.74 |
|
|
$ |
8.14 |
|
|
Exercised
|
|
|
(101,966 |
) |
|
|
12.47 |
|
|
|
|
|
|
Forfeited and expired
|
|
|
(38,709 |
) |
|
|
13.68 |
|
|
|
|
|
|
Outstanding as of September 30, 2021
|
|
|
301,514 |
|
|
$ |
16.25 |
|
|
|
|
|
|
Granted
|
|
|
62,730 |
|
|
|
66.48 |
|
|
$ |
25.54 |
|
|
Exercised
|
|
|
(125,651 |
) |
|
|
12.92 |
|
|
|
|
|
|
Forfeited and expired
|
|
|
(2,084 |
) |
|
|
19.94 |
|
|
|
|
|
|
Outstanding as of September 30, 2022
|
|
|
236,509 |
|
|
$ |
31.30 |
|
|
|
|
|
|
Granted
|
|
|
40,266 |
|
|
|
64.38 |
|
|
$ |
30.83 |
|
|
Exercised
|
|
|
(21,630 |
) |
|
|
26.16 |
|
|
|
|
|
|
Forfeited and expired
|
|
|
(1,021 |
) |
|
|
18.18 |
|
|
|
|
|
|
Outstanding as of September 30, 2023
|
|
|
254,124 |
|
|
$ |
37.04 |
|
|
|
|
|
|
| Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable [Table Text Block] |
|
As of Year Ended
|
|
Exercisable
|
|
Weighted average remaining contractual life
|
|
Weighted average exercise price
|
|
|
Aggregate intrinsic value (in thousands)
|
|
|
September 30, 2023
|
|
|
97,056 |
|
2.28 years
|
|
$ |
28.13 |
|
|
$ |
2,731 |
|
|
September 30, 2022
|
|
|
39,276 |
|
2.78 years
|
|
$ |
20.26 |
|
|
$ |
3,314 |
|
|
September 30, 2021
|
|
|
51,201 |
|
2.29 years
|
|
$ |
12.28 |
|
|
$ |
1,632 |
|
|
| Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding [Table Text Block] |
|
As of Year Ended
|
|
Number outstanding
|
|
Weighted average remaining contractual life
|
|
Weighted average exercise price
|
|
|
Aggregate intrinsic value (in thousands)
|
|
|
September 30, 2023
|
|
|
254,124 |
|
2.72 years
|
|
$ |
37.04 |
|
|
$ |
9,413 |
|
|
September 30, 2022
|
|
|
236,509 |
|
3.30 years
|
|
$ |
31.30 |
|
|
$ |
17,343 |
|
|
September 30, 2021
|
|
|
301,514 |
|
3.22 years
|
|
$ |
16.25 |
|
|
$ |
8,412 |
|
|
| Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] |
| |
|
Number of shares
|
|
|
Weighted average grant date fair value
|
|
|
Unvested shares as of September 30, 2020
|
|
|
109,070 |
|
|
$ |
12.98 |
|
|
Granted
|
|
|
39,807 |
|
|
|
24.20 |
|
|
Vested
|
|
|
(35,840 |
) |
|
|
12.48 |
|
|
Forfeited
|
|
|
(4,198 |
) |
|
|
15.45 |
|
|
Unvested shares as of September 30, 2021
|
|
|
108,839 |
|
|
$ |
17.14 |
|
|
Granted
|
|
|
29,512 |
|
|
|
65.90 |
|
|
Vested
|
|
|
(37,094 |
) |
|
|
17.78 |
|
|
Forfeited
|
|
|
(2,749 |
) |
|
|
16.84 |
|
|
Unvested share, s as of September 30, 2022
|
|
|
98,508 |
|
|
$ |
31.51 |
|
|
Granted
|
|
|
41,492 |
|
|
|
70.50 |
|
|
Vested
|
|
|
(47,869 |
) |
|
|
30.98 |
|
|
Forfeited
|
|
|
(1,556 |
) |
|
|
15.61 |
|
|
Unvested shares as of September 30, 2023
|
|
|
90,575 |
|
|
$ |
49.92 |
|
|