Balance Sheet Account Detail - Summary of Customers Representing 10% or More of Accounts Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	$ 32,260	$ 39,782
McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	11,186	10,395
Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	9,514	13,147
AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	7,175	13,470
All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Accounts Receivables, net	$ 4,385	$ 2,770
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	34.70%	26.10%
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	29.50%	33.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	22.20%	33.90%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	13.60%	7.00%