Summary of Significant Accounting Policies - Summary of Customers Represent 10% or More of Net Receivables (Detail)	Dec. 31, 2012	Dec. 31, 2011
Oncology Supply [Member]
Revenue, Major Customer [Line Items]
Percentage of net receivables	37.70%	26.80%
McKesson Specialty [Member]
Revenue, Major Customer [Line Items]
Percentage of net receivables	26.00%	54.10%
ICS [Member]
Revenue, Major Customer [Line Items]
Percentage of net receivables	19.10%