Stockholders' Equity Stockholders' Equity (Stock-Based Compensation Plans) (Details) shares in Thousands |
Sep. 30, 2018
shares
|
|---|---|
| Class of Stock [Line Items] | |
| Shares Reserved (in shares) | 1,953 |
| Shares Available to Issue (in shares) | 1,405 |
| Options Outstanding (in shares) | 1,658 |
| Performance Awards Outstanding (in shares) | 526 |
| Amended And Restated 2006 Plan [Member] | |
| Class of Stock [Line Items] | |
| Shares Reserved (in shares) | 0 |
| Shares Available to Issue (in shares) | 0 |
| Options Outstanding (in shares) | 1,435 |
| Performance Awards Outstanding (in shares) | 297 |
| 2017 Plan [Member] | |
| Class of Stock [Line Items] | |
| Shares Reserved (in shares) | 1,953 |
| Shares Available to Issue (in shares) | 1,405 |
| Options Outstanding (in shares) | 223 |
| Performance Awards Outstanding (in shares) | 229 |