INCOME TAXES INCOME TAXES - UNRECOGNIZED TAX BENEFITS (Details) - USD ($) $ in Millions |
Apr. 30, 2018 |
Jan. 31, 2018 |
|---|---|---|
| Income Tax Disclosure [Abstract] | ||
| Unrecognized Tax Benefits | $ 115.6 | $ 115.7 |
| Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued | 5.7 | 5.6 |
| Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 105.8 | $ 105.4 |
| Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit | $ 6.5 |