Restructuring Actions - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013 Position
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 4,800,000
Number of positions reduced	155
Employee separation costs	4,751,000
Restructuring liability to be paid in 2014	2,200,000
Restructuring reserve balance	2,220,000
Accrued compensation and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring reserve balance	2,200,000
Research and development expense
Restructuring Cost and Reserve [Line Items]
Employee separation costs	2,200,000
Selling, general and administrative expense
Restructuring Cost and Reserve [Line Items]
Employee separation costs	$ 2,600,000