Net Loss per Share - Schedule of Antidilutive Securities Excluded from the Computation of Diluted Net Loss per Share (Details) - shares
|
3 Months Ended |
Apr. 30, 2018 |
Apr. 30, 2017 |
| Redeemable convertible preferred stock (as converted) |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
0
|
26,899,852
|
| Redeemable convertible preferred stock warrants (as converted) |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
0
|
54,604
|
| Common stock warrants |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
0
|
122,043
|
| Stock options to purchase common stock | Class A Common Stock |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
3,539,338
|
910,513
|
| Stock options to purchase common stock | Class B Common Stock |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
9,001,291
|
10,340,401
|
| Early exercised stock options |
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
234,646
|
128,609
|