Common Stock - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended															0 Months Ended				12 Months Ended	0 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 2003 LTIP	Dec. 31, 2011 2003 LTIP	Dec. 31, 2010 2003 LTIP	Dec. 31, 2012 Performance units 2003 LTIP	Dec. 31, 2011 Performance units 2003 LTIP	Dec. 31, 2010 Performance units 2003 LTIP	Dec. 31, 2011 Performance units Performance awards made prior to 2011	Dec. 31, 2012 Performance units Performance awards made prior to 2011 2003 LTIP	Dec. 31, 2011 Performance units Performance awards made prior to 2011 2003 LTIP	Dec. 31, 2012 Performance units Performance awards made in 2012 2003 LTIP	Dec. 31, 2011 Stock awards	Dec. 31, 2012 Stock awards 2003 LTIP	Jul. 02, 2012 Restricted Stock Units (RSUs) 2003 LTIP	Mar. 15, 2012 Restricted Stock Units (RSUs) 2003 LTIP	Mar. 05, 2012 Restricted Stock Units (RSUs) 2003 LTIP	Feb. 13, 2012 Restricted Stock Units (RSUs) 2003 LTIP	Dec. 31, 2012 Restricted Stock Units (RSUs) 2003 LTIP	Feb. 13, 2012 Restricted Stock Units (RSUs) 1-year vesting period 2003 LTIP	Feb. 13, 2012 Restricted Stock Units (RSUs) 2-year vesting period 2003 LTIP	Feb. 13, 2012 Restricted Stock Units (RSUs) 3-year vesting period 2003 LTIP	Dec. 31, 2012 Minimum 2003 LTIP	Dec. 31, 2012 Maximum 2003 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distribution of maximum Company's common stock																									11,000,000
Additional awards of options to Director to purchase number of common stock, shares				10,000
Additional awards of options to Director to purchase shares, minimum service period				6 months
Reduction to additional awards of options to Director, as a percent of annual equity grant award, starting next fiscal period				60.00%
Vesting period of options																								0 years 3 months 0 days	3 years 0 months 0 days
Option expiration term				10 years 0 months 0 days
Company's common stock to be awarded including shares forfeited or swapped				1,926,209
Unrecognized expense related to nonvested stock-based compensation arrangements				$ 17
Weighted average period for recognition of unrecognized expense related to nonvested stock-based compensation arrangements				1 year 3 months 0 days
Stock-based compensation expense				17	18	22
Tax benefit related to stock-based compensation expense				6	6	8
Number of stock options granted	518,950			518,950
Aggregate intrinsic value, options exercised during period	$ 52	$ 30	$ 54
Weighted-average grant date fair value of options granted during period				$ 18.67	$ 17.05	$ 12.87
Performance unit awards							224,560	220,305	297,695
Service period for performance units awards		3 years	3 years				3 years
Performance unit awards payouts, minimum											0.00%		0.00%
Performance unit awards payouts, maximum											150.00%		200.00%
Number of years average return on equity is calculated												3 years	3 years
Number of years average sales growth is calculated for certain awards												3 years	3 years
Percent of award based on average return on equity ratio													40.00%
Percent of award based on average sales growth										50.00%			40.00%
Percent of award based on total shareholder return relative to competitors													20.00%
Weighted-average grant date, fair value of performance units							$ 71.73	$ 63.89	$ 56.64							$ 73.53	$ 72.90	$ 71.62	$ 70.81
Additional shares of Company stock received by non-employee Director														1,200	1,200
Stock issued to employees																1,600	700	12,000	9,800	24,100	2,000	1,500	6,300
Vesting period of restricted stock																3 years	2 years	3 years			1 year	2 years	3 years