Stock Benefit Plans (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended				12 Months Ended														1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Restricted Stock [Member]	Dec. 31, 2011 Restricted Stock [Member] Shares granted prior to 2004 [Member]	Dec. 31, 2011 Restricted Stock [Member] Shares granted during 2004 [Member]	Dec. 31, 2011 Restricted Stock [Member] Shares granted during 2005 [Member]	Dec. 31, 2011 Restricted Stock [Member] Certain grants in 2005 [Member]	Dec. 31, 2011 Restricted Stock Units And Performance Stock Units [Member] Shares granted prior to 2004 [Member]	Dec. 31, 2010 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2009 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2006 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Deferred Stock Units [Member]	Dec. 31, 2010 Deferred Stock Units [Member]	Dec. 31, 2009 Deferred Stock Units [Member]	Dec. 31, 2011 Stock Options [Member]	Mar. 16, 2005 Stock Options [Member]	Dec. 31, 2011 Executive Plan 2000 [Member]	Mar. 31, 2007 Employee Stock Purchase Plan 1999 [Member]	Dec. 31, 2011 Employee Stock Purchase Plan 1999 [Member]	May 31, 2007 International Plan [Member]	Dec. 31, 2011 International Plan [Member]
Awards made over the life of the plan																		23,200,000
Stock options vesting percentage																25.00%	25.00%
Stock appreciation percentage above exercise price																15.00%
Weighted-average grant-date fair value	$ 6.67	$ 4.85	$ 4.63							$ 22.81	$ 19.33
Total intrinsic value of options exercised	$ 23.6	$ 0.5	$ 0
Unrecognized compensation cost related to option awards				191.0												21.0
Weighted-average period over which that cost is expected to be recognized, years	1.6
Cash received from the exercise of stock options	111.7	1.5	0
Performance-based restricted stock unit payable range minimum												0.00%
Performance-based restricted stock unit payable range maximum												200.00%
Total fair value of deferred stock units													249.0	170.7	87.9
Vesting period, years					10 years	5 years	7 years	3 years	3 years
Total fair value of restricted stock				$ 0.6
Stock option price percent																				95.00%
Reduction in the shares available																				10,000,000
Issuance of common stock common stock approved by the Board of Directors																			35,600,000		12,000,000
Shares due to shareholder action																					4,000,000
Increase in number of shares available for issuance approved by Board of Directors																						5,000,000
Shares purchased by employees																				1,000,337		133,662
Shares available for issuance under the plan																				5,035,737		3,197,034