Consolidated Balance Sheet (Parenthetical) - $ / shares |
Apr. 30, 2018 |
Jan. 31, 2018 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Common stock, par value | $ 0.0015 | $ 0.0015 |
| Common stock, shares authorized | 200,000,000 | 200,000,000 |
| Common stock, shares issued | 59,245,585 | 59,245,585 |
| Treasury stock, shares | 20,927,954 | 21,083,972 |