Percentage of Revenue from Significant Customers (Detail)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Orencia Royalties from Bristol
Revenue, Major Customer [Line Items]
Revenues, percentage by customer	24.00%	24.00%
Bioprocessing Customer A
Revenue, Major Customer [Line Items]
Revenues, percentage by customer	38.00%	43.00%
Bioprocessing Customer B
Revenue, Major Customer [Line Items]
Revenues, percentage by customer	12.00%	14.00%
Bioprocessing Customer C
Revenue, Major Customer [Line Items]
Revenues, percentage by customer	15.00%