Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions |
1 Months Ended | 3 Months Ended |
|---|---|---|
Jan. 31, 2017 |
Apr. 30, 2017 |
|
| Significant Accounting Policies [Line Items] | ||
| Minimum period warranty of product | 1 year | |
| Goodwill impairment charge | $ 23.5 | $ 23.5 |
| Loss on impairment | $ 0.5 | |
| Expected annualized cost saving | $ 10.0 | |
| Minimum [Member] | ||
| Significant Accounting Policies [Line Items] | ||
| Support agreements | 12 months | |
| Maximum [Member] | ||
| Significant Accounting Policies [Line Items] | ||
| Support agreements | 36 months |