Financial Instruments (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011 Investment	Jun. 30, 2012	Jun. 30, 2011 Investment	Dec. 31, 2011
Financial Instruments (Textual) [Abstract]
Federal Deposit Insurance Corporation guaranteed senior notes issued under the Temporary Liquidity Guarantee Program	$ 88.9		$ 88.9		$ 214.0
Original maturities of commercial paper and short-term debt securities			less than 90 days
Average maturity of marketable securities, months			13 months		14 months
Gain (loss) from sale of strategic equity investments				13.8
Impairments recognized in relation to our publicly-held strategic investments			0
Impairment charges	0.8	5.2	1.3	5.5
Strategic investment portfolio	63.2		63.2		62.8
Venture capital investments	25.5		25.5		23.6
Number of marketable equity Investments Sold		1		1
Stromedix, Inc. [Member]
Business Acquisition [Line Items]
Recognized gain			9.0
Strategic Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost basis of equity securities of certain privately-owned companies and venture capital funds	37.7		37.7		39.2
Net gains realized	$ 2.2	$ (5.5)	$ 13.5	$ 7.6