Restructuring Costs - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Employees	Mar. 31, 2014 Employees	Sep. 30, 2015 USD ($) Employees	Sep. 30, 2014 USD ($)
Restructuring Cost and Reserve [Line Items]
Consolidated charge to earnings | $	$ 223,000		$ 223,000	$ 463,000
Restructuring Plan 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Consolidated charge to earnings | $			$ 223,000
The total number of employees affected by the restructuring plan	28
Number of employees terminated by the restructuring plan	26		26
Restructuring Plan 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Consolidated charge to earnings | $				$ 463,000
The total number of employees affected by the restructuring plan		11
Number of employees terminated by the restructuring plan		11