Nature of the Business - Additional Information (Detail) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 05, 2013 Public Offering Closing On March 2013 [Member]
Nature Of Business [Line Items]
Accumulated deficit	$ (290,663,000)	$ (254,239,000)
Closure of underwritten public offering				211,500,000
Shares of common stock offered				2.0
Price per share of common stock offered				$ 105.75
Net proceeds from public offering		$ 473,900,000	$ 473,900,000	$ 200,900,000
Cash and cash equivalents, description	Expects that it will have sufficient cash and cash equivalents to sustain operations to at least the second half of 2016.