Percentage of Accounts Receivable by Significant Customers (Detail) (Accounts Receivable)	Dec. 31, 2012	Dec. 31, 2011
Orencia Royalties from Bristol
Concentration Risk [Line Items]
Accounts receivable, percentage by customer	31.00%	53.00%
Bioprocessing Customer A
Concentration Risk [Line Items]
Accounts receivable, percentage by customer	21.00%	31.00%
Pfizer Inc
Concentration Risk [Line Items]
Accounts receivable, percentage by customer	38.00%