Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Schedule of Changes in Number of Outstanding Stock Options Under Director Plan, Stock Plan and 2011 Incentive Plan) (Details)

v3.19.1
Stock-Based Compensation (Schedule of Changes in Number of Outstanding Stock Options Under Director Plan, Stock Plan and 2011 Incentive Plan) (Details) - $ / shares
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Stock-Based Compensation [Abstract]    
Options, Outstanding - December 31, 2018 1,380,492  
Options, Awarded 50,769  
Options, Exercised  
Options, Forfeited (120,171)  
Options, Outstanding - March 31, 2019 1,311,090 1,380,492
Options, Exercisable at March 31, 2019 933,496  
Options, Expected to vest March 31, 2019 1,311,090  
Weighted average exercise price per share, Outstanding - December 31, 2018 $ 7.56  
Weighted average exercise price per share, Awarded 2.64  
Weighted average exercise price per share, Exercised  
Weighted average exercise price per share, Forfeited 11.27  
Weighted average exercise price per share, Outstanding - March 31, 2019 7.03 $ 7.56
Weighted average exercise price per share, Exercisable at March 31, 2019 8.34  
Weighted average exercise price per share, Expected to vest March 31, 2019 $ 7.03  
Options, Outstanding - Weighted average remaining contractual term (in years) 4 years 2 months 27 days 4 years 2 months 5 days
Options, Exercisable - Weighted average remaining contractual term (in years) 3 years 6 months 29 days  
Options, Expected to vest - Weighted average remaining contractual term (in years) 4 years 2 months 27 days