Other Income, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other Nonoperating Income (Expense) [Abstract]
Gains on sales of businesses and investments										$ 125.9	$ 4.3	$ 10.2
Net loss on early extinguishment of debt										0	(0.1)	(25.1)
Vendor discounts and credit adjustments										19.4	12.7	24.4
Other income (expense), net										4.9	(4.0)	2.2
Total other income (expense), net	13.9	137.1	[1]	5.3	(6.1)	17.6	(3.1)	(2.1)	0.5	150.2	12.9	11.7
Net proceeds from sale of portion of Facebook										133.5
Gain recorded on sale of portion of Facebook		$ 132.2								$ 132.2	$ 0	$ 0

[1] The three months ended September 30, 2011, includes a pre-tax gain of $132.2 related to the sale of approximately half of our holdings in Facebook, Inc.