Fair Value Measurement (Assets Measured At Fair Value On A Nonrecurring Basis) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total, Impairment charge	$ 9.4	$ 8.1
Total assets	8,212.8	8,966.4	8,281.7
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets held and used, Impairment charge	5.6	2.0
Long-lived assets held for sale or disposal, Impairment charge	3.8	5.8
Total, Impairment charge	9.4	7.8
Long-lived assets held and used, Net book value	4.2	60.3
Long-lived assets held for sale or disposal, Net book value		1.3
Total assets	4.2	61.6
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets held and used, Fair value measurement	4.2	60.3
Long-lived assets held for sale or disposal, Fair value measurement	1.5	1.3
Total, Fair value measurement	$ 5.7	$ 61.6