Share-Based Compensation Plans (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010 Y	Dec. 31, 2009 Y
Share-based employee compensation expense	$ 74.5	$ 69.3	$ 78.6
Unamortized share-based employee compensation, amortization period	5
Unamortized share-based employee compensation	263.3
Option Activity [Roll Forward]
Options outstanding, Balance January 1	24,513,590	40,832,715	23,398,301
Options granted under 2007 Plan	90,000	335,000	22,620,000
Options exercised	(6,034,181)	(14,125,525)	(545,586)
Options forfeited	(268,000)	(2,528,600)	(4,640,000)
Options outstanding, Balance December 31	18,301,409	24,513,590	40,832,715
Options exercisable December 31	9,672,909	7,885,090	16,325,715
Options outstanding, Balance January 1, weighted average exercise price	$ 26.64	$ 29.37	$ 36.87
Options granted under 2007 Plan, weighted average exercise price	$ 45.05	$ 38.86	$ 23.73
Options exercised, weighted average exercise price	$ 28.17	$ 33.03	$ 31.18
Options forfeited, weighted average exercise price	$ 27.15	$ 36.58	$ 39.52
Options outstanding, Balance December 31, weighted average exercise price	$ 26.22	$ 26.64	$ 29.37
Options exercisable December 31, weighted average exercise price	$ 27.85	$ 31.80	$ 37.46
Options Outstanding and Exercisable [Abstract]
Options outstanding	18,301,409
Options exercisable	9,672,909
Black-Scholes Assumptions and Weighted Average Fair Value Per Share for Options Granted [Abstract]
Expected option lives	5.0	5.0	5.0
Risk free interest rate, minimum	0.90%	1.80%	1.70%
Risk free interest rate, maximum	1.80%	2.60%	2.50%
Expected volatility, minimum	27.20%	24.70%	19.60%
Expected volatility, maximum	29.20%	27.00%	24.10%
Dividend yield	2.3% - 2.8%	1.9% - 2.4%	1.5% - 2.5%
Weighted average fair value per option granted	$ 9,570,000	$ 8,250,000	$ 3,620,000
Restricted Stock Activity [Roll Forward]
Restricted shares, Balance January 1	3,026,086	3,471,929	4,473,981
Restricted shares, Shares granted	4,688,716	868,273	664,217
Restricted shares, Shares vested	(1,096,441)	(1,089,136)	(1,426,456)
Restricted shares, Shares forfeited	(165,474)	(224,980)	(239,813)
Restricted shares, Balance December 31	6,452,887	3,026,086	3,471,929
Weighted average per share fair value of shares granted	$ 44.87	$ 36.63	$ 32.87
Weighted average per share fair value at December 31	$ 43.66	$ 41.79	$ 44.04
Exersices Price Range - $23.40 to $29.99 [Member]
Options Outstanding and Exercisable [Abstract]
Range of Exercise Prices, lower range limit	$ 23.40
Range of Exercise Prices, upper range limit	$ 29.99
Options outstanding	16,023,515
Options outstanding, weighted average remaining contractual life	7.2
Options outstanding, weighted average exercise price	$ 23.72
Options exercisable	7,945,515
Options exercisable, weighted average exercise price	$ 24.05
Exersices Price Range - $30.00 to $44.99 [Member]
Options Outstanding and Exercisable [Abstract]
Range of Exercise Prices, lower range limit	$ 30.00
Range of Exercise Prices, upper range limit	$ 44.99
Options outstanding	856,894
Options outstanding, weighted average remaining contractual life	7.1
Options outstanding, weighted average exercise price	$ 37.93
Options exercisable	371,394
Options exercisable, weighted average exercise price	$ 38.24
Exersices Price Range - $45.00 to $52.83 [Member]
Options Outstanding and Exercisable [Abstract]
Range of Exercise Prices, lower range limit	$ 45.00
Range of Exercise Prices, upper range limit	$ 52.83
Options outstanding	1,421,000
Options outstanding, weighted average remaining contractual life	1.0
Options outstanding, weighted average exercise price	$ 47.30
Options exercisable	1,356,000
Options exercisable, weighted average exercise price	$ 47.30
2007 Incentive Award Plan [Member]
Maximum of shares available for issuance	17,000,000
Shares available for grant	6,299,646
Stock Options [Member]
Share-based employee compensation, terms of award	the exercise price of stock option awards may not be less than 100% of the market price of our common stock at the grant date and the option term cannot be longer than ten years from the grant date.
Share-based employee compensation, vesting rights	Generally, stock option grants vest 30% on each of the first two grant date anniversaries and 40% three years from the grant date.
Restricted Stock [Member]
Share-based employee compensation, vesting rights	Restricted shares typically vest at 20% per year, provided the employee remains employed by us.
Performance Restricted Stock Units (PRSUs) [Member]
Share-based employee compensation, vesting rights	Each PRSU represents the right to receive one share of our common stock on vesting. The ultimate number of PRSUs received by the employee depends on the Company's average return on equity over the three year period 2011 through 2013 compared to the average return on equity of a peer group of five principal competitors over the same period. The PRSUs vest over five years.
Restricted Stock Activity [Roll Forward]
Restricted shares, Shares granted	413,909
Weighted average per share fair value of shares granted	$ 48.56
Employee Stock Purchase Plan (ESPP) [Member]
Shares available for grant	9,555,685
Employee Stock Purchase Plan (ESPP) [Abstract]
Discount from market price	95.00%
Maximium percentage of eligible compensation allowable for purchase	10.00%
Shares issued in period	161,929	267,931	418,237
Proceeds from issuance of shares	$ 7.0	$ 9.7	$ 12.0