Revenue Recognition (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Percentage of coverage for lives obtained under commercial plans		85.00%
Percentage of coverage for lives obtained under medicare plans		40.00%
Customer Concentration Risk \| Sales Revenue, Net \| Rhopressa \| Distributor One
Disaggregation of Revenue [Line Items]
Concentration risk percentage	34.00%	34.00%
Customer Concentration Risk \| Sales Revenue, Net \| Rhopressa \| Distributor Two
Disaggregation of Revenue [Line Items]
Concentration risk percentage	32.00%	32.00%
Customer Concentration Risk \| Sales Revenue, Net \| Rhopressa \| Distributor Three
Disaggregation of Revenue [Line Items]
Concentration risk percentage	31.00%	31.00%

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
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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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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