AVP-825 License Agreement (Details) - License Agreement Terms - USD ($)	3 Months Ended	9 Months Ended		42 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate cash payments received from license agreement				$ 70,000,000
Potential proceeds upon achievement of milestones				$ 50,000,000
Licensing revenues	$ 0	$ 0	$ 47,500,000