Revenue - Unsatisfied Performance Obligation - Additional Information (Detail)	Jun. 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-07-01
Revenue From Contract With Customer [Line Items]
Unsatisfied performance obligations, expected to recognize	59.00%
Unsatisfied performance obligations, expected to recognize, period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue From Contract With Customer [Line Items]
Unsatisfied performance obligations, expected to recognize	30.00%
Unsatisfied performance obligations, expected to recognize, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue From Contract With Customer [Line Items]
Unsatisfied performance obligations, expected to recognize	11.00%
Unsatisfied performance obligations, expected to recognize, period