Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized tax benefits, beginning balance	$ 572.6	[1]	$ 492.0
Decreases for positions taken in prior years	(50.6)		(27.1)
Increases for positions taken in prior years	24.3		53.3
Increases for positions related to the current year	54.8		102.0
Settlements with taxing authorities	(14.4)		(17.4)
Lapsing of statutes of limitations	(21.7)		(30.2)
Unrecognized Tax Benefits	$ 565.0	[1]	$ 572.6	[1]

[1] Of this amount, $564.3 and $535.9 are included in long-term liabilities on the Consolidated balance sheet for 2011 and 2010, respectively. The remainder is included in deferred income taxes and income taxes payable on the Consolidated balance sheet.