Earnings Per Share - Potentially Dilutive Shares Excluded from Diluted EPS Calculation (Details) - shares shares in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Convertible Senior Notes Maturing March 2032 [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Antidilutive securities (in shares) | 7,493 | 7,995 | 7,814 | 7,995 |