Stockholders' Equity - Reconciliation of Transactions Under ATM Agreement (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Net proceeds	$ 813,561	$ 1,185,452
ATM Agreement
Class of Stock [Line Items]
Issuance of common stock (in shares)	5,452,000	4,679,904
Gross proceeds	$ 813,561	$ 1,385,452
Fees	85,093	252,568
Net proceeds	$ 728,468	$ 1,132,884
Average price per share (in dollars per share)	$ 0.15	$ 0.30