Segment Information - Summary of Revenue by Major Customers (Details) - segment	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Segment Reporting [Abstract]
Number of operating segments	1
Customer Concentration Risk \| Sales Revenue, Net \| AmerisourceBergen Corp.
Revenue, Major Customer [Line Items]
Percentage of total revenues	21.00%	21.00%
Customer Concentration Risk \| Sales Revenue, Net \| Cardinal Health, Inc.
Revenue, Major Customer [Line Items]
Percentage of total revenues	20.00%	21.00%
Customer Concentration Risk \| Sales Revenue, Net \| McKesson Corp.
Revenue, Major Customer [Line Items]
Percentage of total revenues	20.00%	20.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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