Customer, Supplier and Product Concentration - Additional Information (Details) - customer	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Risks and Uncertainties [Abstract]
Number of customers considered as concentration risks	3	3	3	3
Prescription Pharmaceuticals \| Net Revenue \| Segment Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	88.90%	90.20%	89.10%	89.70%

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.

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