FAIR VALUE MEASUREMENTS - OTHER FAIR VALUE DISCLOSURES (Details) - USD ($)
$ in Thousands |
3 Months Ended |
12 Months Ended |
Apr. 30, 2018 |
Jan. 31, 2018 |
| Term Loans | Level 3 |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| Term Loans - Fair Value |
$ 425,000
|
$ 425,000
|
| 1.50% Convertible Senior Notes | Level 2 |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| 1.50% Convertible Senior Notes - Fair Value |
$ 390,000
|
$ 389,000
|
| Minimum | Contingent Consideration |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| Fair Value Inputs, Discount Rate |
3.00%
|
3.00%
|
| Minimum | Option to Acquire Noncontrolling Interests |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| Fair Value Inputs, Discount Rate |
13.00%
|
|
| Maximum | Contingent Consideration |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| Fair Value Inputs, Discount Rate |
|
5.00%
|
| Maximum | Option to Acquire Noncontrolling Interests |
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
| Fair Value Inputs, Discount Rate |
|
13.50%
|