Warrants Outstanding and Exercisable (Details) shares in Thousands	Dec. 31, 2016 $ / shares shares	Dec. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares
Warrant, exercise price	$ 2.23	$ 3.34	$ 3.08
Warrants, Outstanding as of end of period | shares	3,761
Warrants outstanding, weighted average exercise price	2.23
Warrants, Exercisable at end of period | shares	3,761
Warrants exercisable, weighted average exercise price	$ 2.23
$1.76 - $3.08
Warrant exercise, mimimum	1.76
Warrant exercise price, maximum	3.08
Warrants, Outstanding as of end of period | shares	3,761
Warrants outstanding, weighted average remaining contractual life, years	1.38
Warrants outstanding, weighted average exercise price	2.23
Warrants, Exercisable at end of period | shares	3,761
Warrants exercisable, weighted average exercise price	$ 2.23