Percentage of Accounts Receivable by Significant Customers (Detail) (Accounts Receivable)	Jun. 30, 2012	Dec. 31, 2011
Bristol Myers Squibb Company
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	35.00%	31.00%
Bioprocessing customer B
Concentration Risk [Line Items]
Accounts receivable, percentage by customer	21.00%	7.00%