Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Mar. 31, 2012	Dec. 31, 2013 Cash	Dec. 31, 2012 New York	Dec. 31, 2013 San Francisco Lease One	Dec. 31, 2013 San Francisco Lease Two	Dec. 31, 2013 San Francisco Lease Three	Dec. 31, 2013 San Francisco Lease Four
Commitments and Contingencies [Line Items]
Lease agreement commencement date						Apr. 01, 2011	Sep. 01, 2012	Jun. 01, 2013	Dec. 01, 2013
Lease agreement expiration date					Jan. 31, 2014	Jun. 01, 2019	Jun. 01, 2019	Jun. 01, 2019	Jun. 01, 2019
Lease agreement renewal term					1 year	5 years	5 years	5 years	5 years
Lease agreement extended expiration date						Jun. 01, 2024	Jun. 01, 2024	Jun. 01, 2024	Jun. 01, 2024
Rental expense	$ 0.6	$ 1.9	$ 0.5
Sublease rental expense	0.5	0.6	0.4
Minimum rental expense	0.1	1.3	0.1
Security deposit made under lease agreement				0.2
Security deposit made under lease agreement		0.2
Maximum cash pledged		5.0
Pledged and restricted to support contingent obligation		$ 3.4