Revenue - Remaining Performance Obligations (Detail 1)	Sep. 30, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2018-10-01
Remaining Performance Obligations [Line Items]
Remaining performance obligations, expected satisfaction, percentage	80.00%
Remaining performance obligations, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-10-01
Remaining Performance Obligations [Line Items]
Remaining performance obligations, expected satisfaction, percentage	20.00%
Remaining performance obligations, expected timing of satisfaction