Income Taxes - Income Tax Benefit (Expense) from Continuing Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Current Income Tax Expense									$ (43.3)	$ (43.4)	$ (42.6)
Deferred Income Tax Benefit (Expense)									12.9	35.2	(25.1)
Unrecognized Tax Benefit									(0.2)	1.6	3.9
Income Tax Expense	$ 4.3	$ (25.9)	$ 5.1	$ (14.1)	$ (6.1)	$ 6.1	$ 11.5	$ (18.1)	$ (30.6)	$ (6.6)	$ (63.8)