Revenue Accounted for 10% or More of Total Revenues (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Novartis AG ("Novartis")
Concentration Risk [Line Items]
Percentage of major customers revenue accounted for 10% or more of total revenues		100.00%		100.00%
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")
Concentration Risk [Line Items]
Percentage of major customers revenue accounted for 10% or more of total revenues	43.00%		54.00%
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")
Concentration Risk [Line Items]
Percentage of major customers revenue accounted for 10% or more of total revenues	51.00%		43.00%