Leases, Licensed Technology and Other Commitments (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011 Employee sqft	Dec. 31, 2010	Dec. 31, 2009
Lease Commitments and Contingencies [Line Items]
Square footage of office and laboratory facility acquired through non-cancelable operating lease	100,000
Operating lease expiration date	July 2019
Operating lease, number of renewal options	2
Operating lease, renewal options in years	5 years
Operating lease, letters of credit outstanding	$ 699,000
Operating lease rent expense, sublease income	67,000	28,000
Operating lease rent expense net of sublease income	2,000,000	2,100,000	2,100,000
Operating lease, future lease payments due current	3,300,000
Operating lease, future lease payments due in two years	5,200,000
Operating lease, future lease payments due in three years	5,300,000
Operating lease, future lease payments due in four years	5,400,000
Operating lease, future lease payments due in five years	5,500,000
Operating lease, future lease payments due after five years	14,500,000
Operating lease, future sublease rental income in one year	39,000
License fees paid	145,000	145,000	145,000
Future expected annual license fees	145,000
Number of officers under employment agreements	8
Number of years officers are under employment agreements	2 years
Aggregate base salaries payable to officers, due next year	3,000,000
Aggregate base salaries payable to officers, due in two years	$ 1,500,000