Goodwill and Other Intangible Assets - Changes in Goodwill and Other Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance			$ 1,163.7
Impairments
Amortization expense	(43.2)	(39.2)	(129.6)	(117.7)
Foreign currency translation			0.3
Ending Balance	1,034.4		1,034.4
Beginning Balance			3,360.4
Impairments	(247.0)		(247.0)
Additions			7.5
Amortization expense
Contribution of Thistledown to joint venture			(20.1)
Foreign currency translation
Ending Balance	3,100.8		3,100.8
Beginning Balance			3,199.5
Other, Impairment			(192.0)
Amortization expense
Foreign currency translation			0.8
Ending Balance	$ 3,008.3		$ 3,008.3