Business Restructuring - Reconciliation of Restructuring Liability (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended	12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2015	Dec. 31, 2014
2014 Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges				$ 1,722
2014 Restructuring [Member] | Severance Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liability at Beginning Balance			$ 1,722		$ 1,722
Amounts paid					(1,695)
Foreign currency translation					(18)
Expense adjustment					(9)
Restructuring liability at Ending Balance	$ 0			1,722	0	$ 1,722
2013 Restructuring [Member] | Severance Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liability at Beginning Balance	94	$ 186	563		563	1,040
Amounts paid	(23)	(96)	(338)			(420)
Foreign currency translation	(5)	4	(39)			(57)
Restructuring liability at Ending Balance	$ 66	$ 94	$ 186	$ 563	$ 66	$ 563