Balance Sheet Account Detail - Summary of Customers Representing 10% or More of Accounts Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 29,873	$ 32,260
AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	10,448	7,175
Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	8,228	9,514
McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	7,615	11,186
All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 3,582	$ 4,385
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] | AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	35.00%	22.20%
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	27.50%	29.50%
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	25.50%	34.70%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	12.00%	13.60%