CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Details) - USD ($)
$ in Thousands |
3 Months Ended |
|
Apr. 30, 2018 |
Apr. 30, 2017 |
Jan. 31, 2018 |
| Schedule of Available-for-sale Securities |
|
|
|
| Maturities and sales of investments |
$ 0
|
$ 300
|
|
| Corporate debt securities (available-for-sale) |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
2,010
|
|
$ 2,002
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
2,010
|
|
2,002
|
| Bank time deposits |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
7,210
|
|
4,564
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
7,210
|
|
4,564
|
| Total short-term investments |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
9,220
|
|
6,566
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
9,220
|
|
6,566
|
| Cash and bank time deposits |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
341,974
|
|
337,756
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
341,974
|
|
337,756
|
| Money market funds |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
40,263
|
|
186
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
40,263
|
|
186
|
| Total cash and cash equivalents |
|
|
|
| Schedule of Available-for-sale Securities |
|
|
|
| Cost basis |
382,237
|
|
337,942
|
| Gross unrealized gains |
0
|
|
0
|
| Gross unrealized losses |
0
|
|
0
|
| Estimated Fair Value |
$ 382,237
|
|
$ 337,942
|