Restructuring Actions - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2014 USD ($) Position
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 4.8
Number of positions reduced | Position	155
Research and development expense
Restructuring Cost and Reserve [Line Items]
Employee separation costs	$ 2.2
Selling, general and administrative expense
Restructuring Cost and Reserve [Line Items]
Employee separation costs	$ 2.6