Revenue - Additional Information (Detail 1) $ in Millions	Mar. 31, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Deferred revenue expect to recognize amount	$ 7.3
Deferred revenue expect to recognize period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Deferred revenue expect to recognize amount	$ 9.5
Deferred revenue expect to recognize period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Deferred revenue expect to recognize amount	$ 50.7
Deferred revenue expect to recognize period