Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	May 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Lease cancellation notice period		30 days
Commitment maturing in the next fiscal year		$ 25,300,000
Other Commitment, Due in Second Year		2,600,000
Lease term expiration date		Mar. 31, 2020
Tenant improvement allowance	3,200,000	127,000	879,000		1,800,000
Early termination right effective date		Mar. 31, 2018
Term of optional lease extension	3 years
Rent expense		$ 1,200,000	$ 803,000	$ 800,000