Financial Instruments and Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value Measurements [Line Items]
Goodwill impairment	$ 0	$ 0	$ 0
Franchise rights impairment	4.2	0	0
Continuing Operations [Member] | Carrying Value [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	70.4	70.1
Discontinued Operations [Member] | Carrying Value [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	43.2	49.5
Nonrecurring [Member] | Continuing Operations [Member] | Long Lived Assets, Fair Value Disclosure, Adjustments [Member]
Fair Value Measurements [Line Items]
Impairment of long-lived assets held for sale	0	1.1
Nonrecurring [Member] | Continuing Operations [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Impairment of long-lived assets held and used	0.8	1.1
Impairment of long-lived assets held for sale		1.5
Nonrecurring [Member] | Continuing Operations [Member] | Long Lived Assets, Fair Value Disclosure, Write-down Gain [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale fair value adjustment		0.4
Nonrecurring [Member] | Continuing Operations [Member] | Carrying Value [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Long-lived assets held and used measured at fair value		16.9
Long-lived assets held for sale measured at fair value		14.4
Nonrecurring [Member] | Continuing Operations [Member] | Carrying Value [Member] | Long Lived Assets, Fair Value Disclosure, Write-down Gain [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value		0.6
Nonrecurring [Member] | Discontinued Operations [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Impairment of long-lived assets held for sale	0.1	0.5
Nonrecurring [Member] | Discontinued Operations [Member] | Carrying Value [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	3.8	11.4
Nonrecurring [Member] | Level 3 [Member] | Fair Value [Member] | Long Lived Assets, Fair Value Disclosure, Adjustments [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	3.7	24.8
Nonrecurring [Member] | Level 3 [Member] | Continuing Operations [Member] | Fair Value [Member] | Long Lived Assets, Fair Value Disclosure, Adjustments [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	0	13.9
Nonrecurring [Member] | Level 3 [Member] | Continuing Operations [Member] | Fair Value [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Long-lived assets held and used measured at fair value	0	15.8
Long-lived assets held for sale measured at fair value		12.9
Nonrecurring [Member] | Level 3 [Member] | Continuing Operations [Member] | Fair Value [Member] | Long Lived Assets, Fair Value Disclosure, Write-down Gain [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value		1.0
Nonrecurring [Member] | Level 3 [Member] | Discontinued Operations [Member] | Fair Value [Member] | Long Lived Assets, Fair Value Disclosure, Impairment Loss [Member]
Fair Value Measurements [Line Items]
Long-lived assets held for sale measured at fair value	3.7	10.9
Goodwill [Member]
Fair Value Measurements [Line Items]
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test	April 30	April 30	April 30
Franchise rights [Member]
Fair Value Measurements [Line Items]
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test	April 30	April 30	April 30
Franchise rights [Member] | Nonrecurring [Member]
Fair Value Measurements [Line Items]
Franchise rights impairment	$ 4.2	$ 0	$ 0