Stockholders' Equity - Warrants (Details)	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Warrants
Warrants outstanding beginning balance | shares	123,037
Warrants issued | shares	58,332
Warrants outstanding ending balance | shares	181,369
Weighted average exercise price
Beginning balance (in dollars per share) | $ / shares	$ 6.35
Issued (in dollars per share) | $ / shares	8.10
Ending balance (in dollars per share) | $ / shares	$ 6.91