Balance Sheet Account Detail - Summary of Customers Representing 10% or More of Accounts Receivables (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	$ 39,782	$ 30,384
McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	10,395	20,281
Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	13,147	7,241
Oncology Supply, a division of ASD Specialty Healthcare, Inc., and its affiliates (excluding ICS) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	13,470
All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	$ 2,770	$ 2,862
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	100.00%	100.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	26.10%	66.70%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	33.00%	23.80%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Cardinal Health, Inc. and its affiliates [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	10.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Oncology Supply, a division of ASD Specialty Healthcare, Inc., and its affiliates (excluding ICS) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	33.90%	0.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	7.00%	9.40%