Schedule of Performance Obligation (Detail)	9 Months Ended
	Sep. 30, 2020
Hardware Products
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Performance Obligation	Hardware products
When Performance Obligation is Typically Satisfied	When customer obtains control of the product (point-in-time)
When Payment is Typically Due	Within 30-60 days of shipment
How Standalone Selling Price is Typically Estimated	Observable in transactions without multiple performance obligations
Software Licenses
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Performance Obligation	Software licenses
When Performance Obligation is Typically Satisfied	When license is delivered to customer or made available for download, and the applicable license period has begun (point-in-time)
When Payment is Typically Due	Within 30-60 days of the beginning of license period
How Standalone Selling Price is Typically Estimated	Established pricing practices for software licenses bundled with software maintenance, which are separately observable in renewal transactions
Professional Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Performance Obligation	Professional services
When Performance Obligation is Typically Satisfied	As services are performed and/or when the contract is fulfilled (point-in-time)
When Payment is Typically Due	Within 30-60 days of delivery
How Standalone Selling Price is Typically Estimated	Observable in transactions without multiple performance obligations
Software Maintenance and Support Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Performance Obligation	Software maintenance and support services
When Performance Obligation is Typically Satisfied	Ratably over the course of the support contract (over time)
When Payment is Typically Due	Within 30-60 days of the beginning of the contract period
How Standalone Selling Price is Typically Estimated	Observable in renewal transactions
Extended Hardware Warranties
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Performance Obligation	Extended hardware warranties
When Performance Obligation is Typically Satisfied	Ratably over the course of the support contract (over time)
When Payment is Typically Due	Within 30-60 days of the beginning of the contract period
How Standalone Selling Price is Typically Estimated	Observable in renewal transactions