Leases - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
|
| Lessee, Lease, Description [Line Items] | ||
| Option to extend lease (in years) | 5 years | |
| Future noncancellable lease payments | $ 10.2 | |
| Term of contract for lease not yet commenced (in years) | 7 years | |
| Rent expense and related expenses | $ 1.5 | |
| Minimum | ||
| Lessee, Lease, Description [Line Items] | ||
| Remaining lease term (in years) | 1 year | |
| Maximum | ||
| Lessee, Lease, Description [Line Items] | ||
| Remaining lease term (in years) | 8 years | |