Stockholders' Equity (Restricted Stock) (Details) - Restricted stock units - 2014 Plan and Inducement Plan - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stockholders' Equity, other disclosures
Requisite service period, quarterly	4 years
Requisite service period, annually	3 years
Stock-based compensation expense	$ 0.5	$ 0.3
Unrecognized compensation costs (in dollars)	$ 4.9
Weighted average period over which unrecognized compensation costs are expected to be recognized	2 years 4 months 13 days
Number of shares
Balance at beginning of the period	430,733
Granted	375,941
Vested	(115,295)
Restricted stock units withheld for tax	46,420
Balance at end of the period	737,799
Weighted average grant date fair value
Balance at beginning of the period	$ 7.99
Granted	8.60
Vested	8.40
Restricted stock units withheld for tax	8.44
Balance at end of the period	$ 8.27