Commitments and Contingencies (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
Jan. 31, 2019 |
|
| Operating Leased Assets [Line Items] | |||
| Deferred rent | $ 3.8 | $ 3.7 | |
| Rent expense | 1.3 | $ 1.2 | |
| Accrued expenses and other current liabilities | |||
| Operating Leased Assets [Line Items] | |||
| Deferred rent | 0.5 | 0.3 | |
| Other liabilities | |||
| Operating Leased Assets [Line Items] | |||
| Deferred rent | $ 3.3 | $ 3.4 | |