Fair Value Measurements, Assets and Liabilities Measured On A Nonrecurring Basis (Details) (USD $) In Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Cost Method Investee, Privately Held Companies	Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Cost Method Investee, Privately Held Companies	Sep. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Cost Method Investee, Privately Held Companies	Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Cost Method Investee, Privately Held Companies	Dec. 31, 2010 Fair Value, Measurements, Nonrecurring [Member] Cost Method Investee, Privately Held Companies	Sep. 30, 2011 Cost Method Investee, Privately Held Companies	Dec. 31, 2010 Cost Method Investee, Privately Held Companies	Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2010 Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments measured on nonrecurring basis				$ 0.4	$ 0.8	$ 51.0	$ 22.1
Loss due to impairment of privately held equity investments measured on a non-recurring basis	1.8	1.8	0
Fair Value Liabilities Measured On Nonrecurring Basis Liabilities								$ 0	$ 0