Major Customers, Partnerships and Strategic Alliances - Juvenile Diabetes Research Foundation International - Additional Information (Detail) (Juvenile Diabetes Research Foundation International [Member], USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Mar. 31, 2012	Jan. 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Juvenile Diabetes Research Foundation International [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Agreement date			Oct. 31, 2006
Grant funding amount maximum under amended agreement		$ 3.0
Received for work performed under agreement	0.8
Revenues under the agreement			$ 0	$ 0	$ 0.8