Commitments and Contingencies - Cystic Fibrosis Foundation Agreement and Joint Venture Agreement (Details) - CF Foundation $ in Millions	1 Months Ended
	Dec. 31, 2016 USD ($) item installment	Nov. 30, 2018 USD ($)
Cystic Fibrosis Foundation Agreement
Amount of award received for advance research on potential drugs | $	$ 2.9	$ 7.5
Period for payment of annual installments	90 days
Maximum percentage of awarded amount of net sales	15.00%
Payment of amount received in connection with Disposition Transaction (as a percent)	15.00%
Number of multiplication on awarded amount payable if change of control prior to completion of the first commercial sale | item	9
Maximum
Cystic Fibrosis Foundation Agreement
Number of annual installments for repayment of award | installment	5