Revenue Accounted for 10% or More of Total Revenues (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
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	21.00%	43.00%	20.00%	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	49.00%	51.00%	44.00%	43.00%
Daiichi Sankyo, Inc ("Daiichi")
Concentration Risk [Line Items]
Percentage of major customers revenue accounted for 10% or more of total revenues	27.00%		34.00%