Business Restructuring - Reconciliation of Restructuring Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost And Reserve [Line Items]
Expense recognized	$ 426			$ 1,798	$ 1,061
Longford Mills Shutdown [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liability	1,010	$ 1,316	$ 1,985	1,985
Expense recognized	426	454	786
Amounts paid	(570)	(783)	(1,478)
Foreign currency translation	51	23	23
Restructuring liability	917	1,010	1,316	917
Longford Mills Shutdown [Member] | Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liability	867	1,015	1,548	1,548
Amounts paid	(126)	(168)	(550)
Foreign currency translation	37	20	17
Restructuring liability	778	867	1,015	778
Longford Mills Shutdown [Member] | Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liability	143	301	437	437
Expense recognized	426	454	786
Amounts paid	(444)	(615)	(928)
Foreign currency translation	14	3	6
Restructuring liability	$ 139	$ 143	$ 301	$ 139