Revenue Recognition (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) distributor	Sep. 30, 2018 USD ($) distributor
Disaggregation of Revenue [Line Items]
Provisions for revenue reserves to reduce product revenues to product revenues, net | $	$ 31.0	$ 6.4	$ 73.8	$ 8.1
Customer Concentration Risk | Sales Revenue, Net | Rhopressa
Disaggregation of Revenue [Line Items]
Number of distributors | distributor			3	3
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor One
Disaggregation of Revenue [Line Items]
Concentration risk percentage			37.00%	34.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor Two
Disaggregation of Revenue [Line Items]
Concentration risk percentage			31.00%	32.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor Three
Disaggregation of Revenue [Line Items]
Concentration risk percentage			30.00%	31.00%