Stockholders' Equity (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Estimated amount of share-based compensation expense
2012	$ 19.6
2013	12.8
2014	6.3
Total	38.7
2012 Three-year PSU Awards [Member]
Estimated amount of share-based compensation expense
2012	2.2
2013	2.8
2014	2.9
Total	7.9
2011 Three-year PSU Awards [Member]
Estimated amount of share-based compensation expense
2012	1.9
2013	2.5
Total	4.4
2010 Three-year PSU Awards [Member]
Estimated amount of share-based compensation expense
2012	2.8
Total	2.8
2012 CEO Incentive Compensation [Member]
Estimated amount of share-based compensation expense
2012	4.0
Total	4.0
SLO Awards [Member]
Estimated amount of share-based compensation expense
2012	0.9
2013	0.3
Total	1.2
Other long-term share-based incentive compensation programs [Member]
Estimated amount of share-based compensation expense
2012	7.8
2013	7.2
2014	3.4
Total	$ 18.4