Contingencies, Commitments and Guarantees - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Commitments [Line Items]
Period of operating lease	2 years
Rent expense	$ 1,500,000	$ 2,900,000	$ 2,200,000
Amount of accrued milestones	0
Indemnification accruals	0
Retinagenix LLC [Member]
Other Commitments [Line Items]
Milestone payment due upon initiation of first pivotal trial	1,000,000
Maximum potential royalty milestone obligations owing to Retinagenix	15,000,000
Special Termination Benefits [Member]
Other Commitments [Line Items]
Contractual termination range of dates	Agreed to terminate him on either, March 31, 2014, April 30, 2014 or May 31, 2014, at the Company's discretion.
Maximum [Member] | Retinagenix LLC [Member]
Other Commitments [Line Items]
Agreed to pay, upon the achievement of other specified development or regulatory milestones	11,500,000
Agreement to pay, achievement of specified development, or regulatory milestones	9,000,000
Percent of royalty payment to Retinagenix	6.00%
Maximum [Member] | Special Termination Benefits [Member]
Other Commitments [Line Items]
Estimated cost of severance and termination benefits	1,100,000
Minimum [Member] | Retinagenix LLC [Member]
Other Commitments [Line Items]
Percent of royalty payment to Retinagenix	4.00%
Minimum [Member] | Special Termination Benefits [Member]
Other Commitments [Line Items]
Estimated cost of severance and termination benefits	$ 1,000,000