Warrants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Jun. 07, 2018	Jun. 06, 2018	Mar. 21, 2018	Mar. 20, 2018	Dec. 31, 2017
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	219,651
Warrants Issued (in shares)	6,246,315
Warrants Exercised (in shares)	(740,460)
Balance at end of the period (in shares)	5,725,506
Common Stock authorized (in shares)	250,000,000	250,000,000	100,000,000	100,000,000	25,000,000	25,000,000
Non-tradable warrants expiring July 2021, Liability
Warrants
Warrant exercise price (in dollars per share)	$ 172.50
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	6,456
Balance at end of the period (in shares)	6,456
Tradable warrants expiring July 2021, Liability
Warrants
Warrant exercise price (in dollars per share)	$ 73.80
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	212,801
Balance at end of the period (in shares)	212,801
Non-tradable pre-funded warrants expiring July 2023, Equity
Warrants
Warrant exercise price (in dollars per share)	$ 0.15
Warrants outstanding and warrant activity
Balance at beginning of the period (in shares)	394
Balance at end of the period (in shares)	394
Non-tradable warrants with exercise price 6.69375 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 6.69375
Warrants outstanding and warrant activity
Warrants Issued (in shares)	663,167
Balance at end of the period (in shares)	663,167
Non-tradable warrants with exercise price 7.96875 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 7.96875
Warrants outstanding and warrant activity
Warrants Issued (in shares)	33,158
Balance at end of the period (in shares)	33,158
Non-tradable warrants with exercise price 14.10 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 14.10
Warrants outstanding and warrant activity
Warrants Issued (in shares)	5,000
Balance at end of the period (in shares)	5,000
Non-tradable warrants with exercise price 21.15 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 21.15
Warrants outstanding and warrant activity
Warrants Issued (in shares)	8,333
Balance at end of the period (in shares)	8,333
Non-tradable warrants with exercise price 7.7895 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 7.7895
Warrants outstanding and warrant activity
Warrants Issued (in shares)	15,000
Balance at end of the period (in shares)	15,000
Non-tradable pre-funded warrants with exercise Price 0.15 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 0.15
Warrants outstanding and warrant activity
Warrants Issued (in shares)	196,167
Warrants Exercised (in shares)	(110,000)
Balance at end of the period (in shares)	86,167
Non-tradable warrants with exercise price 6.375 Equity
Warrants
Warrant exercise price (in dollars per share)	$ 6.375
Warrants outstanding and warrant activity
Warrants Issued (in shares)	4,509,804
Warrants Exercised (in shares)	(76,842)
Balance at end of the period (in shares)	4,432,962
Non-tradable warrants with exercise price 0.15 Equity1
Warrants
Warrant exercise price (in dollars per share)	$ 0.15
Warrants outstanding and warrant activity
Warrants Issued (in shares)	815,686
Warrants Exercised (in shares)	(553,618)
Balance at end of the period (in shares)	262,068