Stockholders' Equity (Details 6) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Estimated amount of share-based compensation expense
2012	$ 15.9
2013	8.1
2014	1.5
Total	25.5
2011 Three-year PSU Awards [Member]
Estimated amount of share-based compensation expense
2012	2.9
2013	2.8
2014	0
Total	5.7
2010 Three-year PSU Awards [Member]
Estimated amount of share-based compensation expense
2012	4.1
2013	0
2014	0
Total	4.1
SLO Awards [Member]
Estimated amount of share-based compensation expense
2012	0.1
2013	0
2014	0
Total	0.1
Other long-term share-based incentive compensation programs [Member]
Estimated amount of share-based compensation expense
2012	8.8
2013	5.3
2014	1.5
Total	$ 15.6