Commitments and Contingencies - 2014 Agreement (Details)							1 Months Ended		2 Months Ended	5 Months Ended	12 Months Ended
	Dec. 22, 2017 USD ($) $ / shares shares	Dec. 21, 2017 USD ($)	Sep. 23, 2017 USD ($) shares	Sep. 22, 2017 USD ($) $ / shares	Sep. 08, 2017 USD ($) installment trading_days	Apr. 25, 2016	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Oct. 22, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)
Other Commitments [Line Items]
Stock issued during period, value, issued for services											$ 882,232		$ 190,427
Stock issued during the period											16,777,666
2014 Consulting Agreement
Other Commitments [Line Items]
Additional consultant fee payable, percentage of perpetuity in excess of $3 million								3.75%		3.75%		3.75%
Sponsor fees												$ 963,600
2016 Consulting Agreement
Other Commitments [Line Items]
Sponsor fees												687,500
Percentage of gross funding up to $20 million						5.00%
Percentage of gross funding over $20 million						3.50%
Accrued liabilities, current								$ 928,500		$ 928,500		928,500
Advisory Services
Other Commitments [Line Items]
Sponsor fees							$ 100,000			439,000	447,000
Other commitment					$ 300,000
Number of installment payments | installment					3
Installment payment period					16 months
Stock issued during period, value, issued for services	$ 100,000	$ 81,000	$ 100,000	$ 133,000	$ 300,000
Milestone payment					$ 140,600
Milestone payment percentage					3.75%
Milestone payment period					15 days
Milestone payment percentage of total consideration with payment					3.375%
Milestone payment percentage of total consideration with payment and additional provision					3.5625%
Milestone period					6 years
Milestone payment percentage of total consideration without payment					3.45525%
Milestone payment percentage of total consideration without payment and with additional provision					3.60263%
Threshold trading days | trading_days					10
Stock issued during period for services (in shares) | shares	3,455		3,283
Share price of stock issued (in dollars per share) | $ / shares	$ 24.95			$ 40.58
Payments for other commitment fees			$ 240,600					100,000	$ 340,600
Accrued liabilities							$ 151,000	$ 639,000		$ 639,000	$ 151,000	$ 639,000	$ 200,000
Stock newly-issued during the period (in shares) | shares							6,498
Stock issued during the period	$ 81,000		$ 133,000				$ 200,000