The Company and Summary of Significant Accounting Policies - Additional Information (Detail)	Jun. 30, 2012 Customer	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Number of customers with significant accounts receivable	5
Percentage of gross accounts receivable	71.00%
Express Scripts
Summary Of Significant Accounting Policies [Line Items]
Number of customers with significant accounts receivable	1
Percentage of gross accounts receivable	46.00%	79.00%