Stock-Based Compensation (Narrative) (Details) - Jun. 30, 2015 - USD ($) $ in Millions |
Total |
|---|---|
| Share-based Compensation [Abstract] | |
| Option expiration period (in years) | 10 years |
| Option vesting period (in years) | 4 years |
| Unrecognized compensation expense | $ 344.4 |
| Recognition period | 3 years 2 months 12 days |