Quarterly report pursuant to Section 13 or 15(d)

Common Stock, Stock Options and Warrants - Stock Options Fair Value Assumptions (Details)

v3.5.0.2
Common Stock, Stock Options and Warrants - Stock Options Fair Value Assumptions (Details) - Employee stock options - $ / shares
6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Common stock price on grant date (usd per share) $ 8.45 $ 13.14
Expected life (in years) 3 years 10 months 9 days 4 years
Risk-free interest rate 1.12% 1.31%
Expected stock volatility 45.00% 50.00%
Expected dividend yield 0.00% 0.00%
Fair value of stock options granted (usd per share) $ 2.97 $ 5.37