Fair Value Measurements (Details) (Fair Value Measurements Recurring [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets (liabilities) measured at fair value on a recurring basis
Fair Value of Derivative	$ (2.8)	$ (3.5)
Asset held for sale	1.8	1.8
Level 1 [Member]
Assets (liabilities) measured at fair value on a recurring basis
Fair Value of Derivative	0	0
Asset held for sale	0	0
Level 2 [Member]
Assets (liabilities) measured at fair value on a recurring basis
Fair Value of Derivative	(2.8)	(3.5)
Asset held for sale	1.8	1.8
Level 3 [Member]
Assets (liabilities) measured at fair value on a recurring basis
Fair Value of Derivative	0	0
Asset held for sale	$ 0	$ 0