Warrants (Details) - Warrants - Common stock - $ / shares	Sep. 30, 2017	Dec. 31, 2016
2017
Warrants
Warrant shares (in shares)		6,250
Exercise price (in dollars per share)		$ 128.00
2019
Warrants
Warrant shares (in shares)	7,030	7,030
Exercise price (in dollars per share)	$ 128.00	$ 128.00
2019
Warrants
Warrant shares (in shares)	130	130
Exercise price (in dollars per share)	$ 2,520.00	$ 2,520.00