Common Stock - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended			6 Months Ended
	Jan. 31, 2013	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation, effect on earnings per share, basic		$ 0.02		$ 0.05
Share-based compensation, effect on earnings per share, diluted				$ 0.03
Share based compensation		$ 2	$ 3		$ 7	$ 7
Weighted average grant-date fair value of options granted				$ 17.49	$ 19.84
Total fair value of shares vested				3	3
Stock Repurchased during Period, Shares	550,000	45,000
Purchase of common stock through stock repurchase program		2
Treasury Stock Acquired, Average Cost Per Share		$ 44.56
Treasury Stock, Shares		2,339,692			2,339,692		2,294,692
Stock repurchase duration in 2012					12 months
Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		8			8
Unrecognized compensation costs, weighted average period					1 year 8 months 12 days
Cash received from stock option exercises					10	2
Unrecorded tax benefit from stock options exercised					3	1
Restricted Stock, Restricted Stock Units, Long Term Performance Units, SARs [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		18			18
Unrecognized compensation costs, weighted average period					2 years 1 month 6 days
Share based compensation		5	2		8	8
Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		9			9
Unrecognized compensation costs, weighted average period					2 years 0 months 0 days
Total fair value of restricted shares vested					5	4
Selling, General and Administrative Expenses [Member] | Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense related to nonqualified stock options		$ 1	$ 1		$ 3	$ 3