INCOME TAXES - Changes in Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Balance, beginning of year | $ 14,827 | $ 7,968 | $ 13,820 |
| Increases for tax positions of prior years | 0 | 7,886 | 839 |
| Decreases for tax positions of prior years | 0 | 0 | (5,890) |
| Increases based on tax positions related to the current year | 1,420 | 882 | 378 |
| Decreases due to lapse of statute of limitation | (721) | (1,909) | (1,179) |
| Balance, end of year | $ 15,526 | $ 14,827 | $ 7,968 |
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|