Revenue from Contracts with Customers - Remaining Performance Obligations - Additional Information (Detail) |
Dec. 31, 2020 |
|---|---|
| Maintenance and Support Contracts for Email Software Licenses | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01 | |
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
| Revenue, remaining performance obligation, expected timing of satisfaction, period | 12 months |