Business Acquisitions Disposition of Assets and Asset Impairments (Details 1) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Components of the loss on disposition of assets and impairments, net
Gain on disposition of assets, net	$ (17.1)		$ (17.1)
Loss on disposition of assets and impairments, net	19.4	1.1	19.0	1.6
Southern Region [Member]
Components of the loss on disposition of assets and impairments, net
Asset impairment	28.5		28.5
Western Region [Member]
Components of the loss on disposition of assets and impairments, net
Asset impairment	7.2		7.2
All other, net [Member]
Components of the loss on disposition of assets and impairments, net
Loss on disposition of assets and impairments, net	$ 0.8		$ 0.4