Summary of Segment Activity in Restructuring Accrual (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring charge	$ (77)	$ 2,945
Cash payments		(2,901)
Restructuring accrual balance at September 30, 2017	44	44
Americas
Restructuring Cost And Reserve [Line Items]
Restructuring charge	(77)	2,831
Cash payments		(2,793)
Restructuring accrual balance at September 30, 2017	38	38
EMEA
Restructuring Cost And Reserve [Line Items]
Restructuring charge		114
Cash payments		(108)
Restructuring accrual balance at September 30, 2017	$ 6	$ 6