Capitalized Fees Paid to a Related Party (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Capitalized Fees paid to a Related Party
Capitalized fees paid to a related party, useful life	15 years
GSK
Capitalized Fees paid to a Related Party
Capitalized fees paid to a related party	$ 220.0
Accumulated amortization of capitalized fees	$ 49.8