Revenue from Contracts with Customers - Revenue Recognition (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-05-01 |
Apr. 30, 2019 |
|---|---|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
| Percentage of revenue related to remaining performance obligations | 98.00% |
| Period of expected timing of satisfaction related to remaining performance obligations | 12 months |