Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues	$ 32.1	$ 66.5
Loss from discontinued operations before income taxes	(16.6)	(9.1)
Income tax benefit	7.5	4.4
Loss from discontinued operations, net of income taxes	(9.1)	(4.7)
Other current assets	31.2		37.5
Investments and other assets	142.3		140.8
Total assets classified as discontinued operations	173.5		178.3
Accounts payable and accrued expenses	29.3		33.3
Other noncurrent liabilities	40.0		27.1
Total liabilities classified as discontinued operations	$ 69.3		$ 60.4