Revenue Recognition - Summary of Transaction Price Allocated to Future Performance Obligations (Detail) $ in Thousands	Jun. 30, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	$ 26,087
Deferred Revenue [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	15,447
Unbilled Backlog [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	10,640
Current [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	22,203
Current [Member] | Deferred Revenue [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	13,771
Current [Member] | Unbilled Backlog [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	8,432
Long-term [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	3,884
Long-term [Member] | Deferred Revenue [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	1,676
Long-term [Member] | Unbilled Backlog [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	$ 2,208