Restructuring Charges - Additional Information (Detail) $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Percentage of reduction of global workforce	6.00%
Reduction in salary, wages and other employee-related expenses due to implementation of plan	$ 1.8

The number of positions eliminated during the period as a percentage of total positions eliminated during the period in connection with the restructuring plan(s).

No definition available.

Name:	us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration