Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Narrative) (Details)

v3.5.0.2
Stock-Based Compensation (Narrative) (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2016
Jun. 30, 2015
Restricted Stock Units [Member]      
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Unrecognized costs related to share based compensation $ 17,070,000 $ 17,070,000  
Weighted average period of recognition of unrecognized costs related to stock options, years 2 years 4 months 17 days    
Restricted stock units granted (in shares)   188,719 194,591
Employee Stock Options [Member]      
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]      
Stock options granted (in shares)   422,973 495,145
Unrecognized costs related to share based compensation $ 8,931,000 $ 8,931,000  
Weighted average period of recognition of unrecognized costs related to stock options, years 2 years 6 months 22 days