Warrants - Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares
Outstanding at beginning of period (in shares)	1,610,069	1,139,535
Issued (in shares)	2,957,138	1,448,964
Exchange warrants issued (in shares)	856,393
Exchange warrants surrendered (in shares)	(856,393)
Exercised (in shares)		(968,571)
Expired (in shares)		(9,859)
Outstanding at end of period (in shares)	4,567,207	1,610,069
Exercisable at end of period (in shares)	2,939,814
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 3.54	$ 1.68
Issued (in dollars per share)	0.90	3.32
Exercised (in shares)		1.03
Exchange warrants (in dollars per share)	1.70
Exchange warrants surrendered (in dollars per share)	3.19
Expired ( in dollars per share)		2.80
Outstanding at end of period (in dollars per share)	1.49	3.54
Exercisable at end of period (in dollars per share)	1.37
Range of Exercise Prices
Exchange warrants issued (in dollars per share)	$ 1.70
Expired (in dollars per share)		$ 2.80
Equity classified as warrants	170,676	170,676	170,676
Minimum
Range of Exercise Prices
Outstanding at beginning of period (in dollars per share)	$ 1.25	$ 1.25
Issued (in dollars per share)	0.01	0.01
Exercised (in dollars per share)		0.01
Exchange warrants surrendered (in dollars per share)	2.65
Outstanding at end of period (in dollars per share)	0.01	1.25
Exercisable (in dollars per share)	0.01
Maximum
Range of Exercise Prices
Outstanding at beginning of period (in dollars per share)	10.40	10.40
Issued (in dollars per share)	2.65	4.20
Exercised (in dollars per share)		1.25
Exchange warrants surrendered (in dollars per share)	4.20
Outstanding at end of period (in dollars per share)	4.50	$ 10.40
Exercisable (in dollars per share)	$ 4.50