Subsequent Events - Additional Information (Detail) (Subsequent Event) In Millions, except Share data, unless otherwise specified	1 Months Ended	0 Months Ended		1 Months Ended
	Oct. 31, 2014 USD ($)	Nov. 07, 2014 Lonza Sales AG USD ($)	Nov. 07, 2014 Lonza Sales AG EUR (€)	Oct. 31, 2014 Lonza Sales AG Cancellation Fee	Oct. 31, 2014 Minimum Lonza Sales AG USD ($) AlfaCommercialBatch	Oct. 31, 2014 Minimum Lonza Sales AG EUR (€)	Oct. 31, 2014 Minimum Lonza Sales AG Cancellation Fee USD ($)	Oct. 31, 2014 Minimum Lonza Sales AG Cancellation Fee EUR (€)	Oct. 31, 2014 Maximum Lonza Sales AG USD ($)	Oct. 31, 2014 Maximum Lonza Sales AG EUR (€)	Oct. 31, 2014 Maximum Lonza Sales AG Cancellation Fee USD ($)	Oct. 31, 2014 Maximum Lonza Sales AG Cancellation Fee EUR (€)	Oct. 31, 2014 Underwritten Public Offering USD ($)	Oct. 31, 2014 Over-Allotment Option USD ($)
Subsequent Event [Line Items]
Common stock initial public offering													6,200,000
Common stock issued per share													$ 26.00	$ 26.00
Purchase of additional shares by underwriters														930,000
Underwriting discounts, commissions and offering expenses	$ 10.7
Proceeds from public offering, net of underwriters discounts, commissions and offering expenses	174.7
Minimum purchases per year					7	7
Termination fees payment under obligation					12.7	10.0	12.7	10.0	19.0	15.0	16.9	13.3
Purchase commitment period				5 years
Upfront payment for agreement		1.5	1.2
Milestone payment		$ 3.2	€ 2.5