Leases - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Nov. 30, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 28, 2011 sqft	Sep. 30, 2009 sqft
Leases [Line Items]
Percentage ceiling on rent increases, annually, capital lease		3.00%
San Carlos facility capital leases termination date		Oct. 05, 2016
Impairment charge	$ 12,600,000
Operating sublease						102,283
Operating Sublease term commenced start date		August 2010
Operating Sublease term commenced period		114 months
Operating Sublease term commenced end date		January 31, 2020
Initial monthly base rent per square foot, operating lease		2.95
Final monthly base rent per square foot, operating lease		3.42
Additional area included in operating sublease due to amendment					24,002
Operating lease expense per month per amendment		40,000
Rent expense for operating leases		$ 2,800,000	$ 2,400,000	$ 2,200,000