Summary of Significant Accounting Policies (Details) - USD ($) |
3 Months Ended | |||
|---|---|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
Feb. 01, 2019 |
Jan. 31, 2019 |
|
| Accounting Policies [Abstract] | ||||
| Related party transactions | $ 0 | $ 0 | ||
| Amounts payable to or receivable from related parties | 0 | $ 0 | ||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Deferred rent credit | 12,378,000 | $ 0 | ||
| Lease liability | $ 13,402,000 | |||
| Cumulative effect of accounting change | $ 4,103,000 | |||
| Accumulated Deficit | ||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Cumulative effect of accounting change | 4,103,000 | |||
| Accounting Standards Update 2016-19 | ||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Deferred rent credit | 53,700,000 | |||
| Deferred revenue | 2,900,000 | |||
| Lease liability | 70,200,000 | |||
| Accounting Standards Update 2016-19 | Accumulated Deficit | ||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||
| Cumulative effect of accounting change | $ 4,100,000 | |||