Subsequent Event (Details) - Subsequent Event [Member] - Supply agreement - ITG € in Millions	Jul. 05, 2018 EUR (€)
Subsequent Event [Line Items]
Upfront cash payment	€ 5
Number of days following the effective date of the agreement within which the upfront payment is required	30 days
Number of years in each successive agreement term extension	2 years
Product required for phase 3 VISION trial
Subsequent Event [Line Items]
Amount of product to be purchased as a percentage of requirements	100.00%
Product volume needs during commercial phase | Minimum
Subsequent Event [Line Items]
Amount of product to be purchased as a percentage of requirements	50.00%
Product volume needs during commercial phase | Maximum
Subsequent Event [Line Items]
Amount of product to be purchased as a percentage of requirements	100.00%