Revenue Recognition - Additional Information (Detail1) $ in Millions	Mar. 31, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 81.9
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 86.5
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 58.1
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 48.9
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 42.7
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 81.7
Revenue, remaining performance obligation, expected timing of satisfaction, period