REVENUE - TIMING OF REVENUE RECOGNITION (Details) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Timing of Revenue Recognition [Roll Forward] | ||
| Customers' credit, beginning | $ 31,297 | $ 38,595 |
| Increase for customers' credits | (8,353) | (15,746) |
| Customers' credit, end | 22,944 | 22,849 |
| Billed | ||
| Timing of Revenue Recognition [Roll Forward] | ||
| Billed, beginning | 109,366 | 105,531 |
| Increase for customer accounts receivable | 181,686 | 157,720 |
| Billed, end | 291,052 | 263,251 |
| Unbilled | ||
| Timing of Revenue Recognition [Roll Forward] | ||
| Billed, beginning | 24,194 | 20,094 |
| Increase for customer accounts receivable | 54,817 | 53,531 |
| Billed, end | $ 79,011 | $ 73,625 |