|
EARNINGS PER SHARE (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
|
| Computation of Basic Income per Share [Abstract] | ||||
| Net income | $ 28.7 | $ 47.2 | $ 115.0 | $ 223.0 |
| Basic shares (in shares) | 80.1 | 80.2 | 80.1 | 79.9 |
| Basic net income per share (in dollars per share) | $ 0.36 | $ 0.59 | $ 1.44 | $ 2.79 |
| Computation of Diluted Income per Share [Abstract] | ||||
| Basic shares (in shares) | 80.1 | 80.2 | 80.1 | 79.9 |
| Stock-based compensation (in shares) | 0.9 | 0.6 | 0.8 | 0.9 |
| Diluted shares (in shares) | 81.0 | 80.8 | 80.9 | 80.8 |
| Diluted net income per share (in dollars per share) | $ 0.35 | $ 0.58 | $ 1.42 | $ 2.76 |
| Antidilutive shares excluded from the computation of earnings per share (in shares) | 1.0 | 1.7 | 1.0 | 0.9 |