Summary of Business and Significant Accounting Policies - Schedule of Certain Risks and Concentrations of Credit Risk (Detail) - Customer concentration risk [Member] - Accounts receivable [Member] |
3 Months Ended | 12 Months Ended |
|---|---|---|
Apr. 30, 2018 |
Jan. 31, 2018 |
|
| Customer 1 [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk percentage | 18.00% | |
| Customer 2 [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk percentage | 13.00% | |
| Customer 3 [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk percentage | 15.00% | |
| Customer 4 [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk percentage | 12.00% |