Stock Based Compensation - Summary of Stock Incentive Plans (Details) - USD ($)		12 Months Ended
	May 12, 2015	Dec. 31, 2019	Dec. 31, 2018
Shares Available for Grant
Beginning balance (in shares)		2,327
Ending balance (in shares)		479,829	2,327
Stock Options Outstanding
Beginning balance (in shares)		42,059
Ending balance (in shares)		3,902,675	42,059
RSUs Outstanding
Beginning balance (in shares)		5,613
Ending balance (in shares)		5,613	5,613
Options vested, exercisable and expected to vest
Weighted average grant date fair value of stock options granted (in dollars per share)		$ 1.54	$ 111.88
Number of options vested (in shares)		944,821	12,590
Weighted average fair value of options vested on grant date		$ 3.12	$ 172.07
Stock-based compensation expense		$ 2,988,544	$ 2,023,874
Inducement options issued and outstanding
Stock Based Compensation
Option shares outstanding		74	2,983
Stock Options Outstanding
Beginning balance (in shares)		2,984
Options granted (in shares)			2,993
Ending balance (in shares)		74	2,984
Options vested, exercisable and expected to vest
Weighted average grant date fair value of stock options granted (in dollars per share)			$ 93.80
Stock-based compensation expense		$ 92,506	$ 52,577
2013 Plan
Stock Based Compensation
Option shares outstanding		395
2014 Plan
Shares Available for Grant
Beginning balance (in shares)		2,327
Additional shares authorized (in shares)		4,338,197
Options granted (in shares)		(4,481,764)
Options cancelled (in shares)		621,069
Ending balance (in shares)		479,829	2,327
Stock Options Outstanding
Beginning balance (in shares)		42,059
Options granted (in shares)		4,481,764
Options cancelled (in shares)		(621,148)
Ending balance (in shares)		3,902,675	42,059
RSUs Outstanding
Beginning balance (in shares)		5,613
Ending balance (in shares)		5,613	5,613
Weighted Average Stock Option Exercise Price
Beginning balance (in dollars per share)		$ 406.36
Options granted (in dollars per share)		1.68
Options cancelled (in dollars per share)		5.51
Ending balance (in dollars per share)		$ 5.20	$ 406.36
Weighted Average Remaining Contractual Life (Years)
Weighted Average Remaining Contractual Life (Years)		9 years 6 months 22 days	9 years 2 months 27 days
Options vested, exercisable and expected to vest
Options vested and exercisable (in shares)		904,051
Options vested and exercisable (in dollars per share)		$ 13.77
Options vested and exercisable (in years)		9 years 5 months 19 days
Options vested and expected to vest (in shares)		3,364,438
Options vested and expected to vest (in dollars per share)		$ 5.69
Options vested and expected to vest (in years)		9 years 6 months 18 days
Options exercised (in shares)		0	0
2014 Plan | Stock options
Stock Based Compensation
Increase in share reserve based on outstanding number of shares (as a percent)	2.00%
Common Stock
Options vested, exercisable and expected to vest
Share Price		$ 0.80