Stock-Based Employee Compensation Plans - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to stock-based compensation plan	$ 89	$ 84	$ 82
Total income tax benefit related to stock-based compensation plan	31	29	29
Unrecognized compensation cost related to nonvested awards	80
Weighted average period of years over which unrecognized compensation cost will be reflected in operating results	1 year 9 months 18 days
Maximum number of shares in respect to which stock-based awards may be granted under the plan most recently approved by shareholders	8,650,000
Shares available for grant	6,891,434
Performance period in which performance unit awards are based	3 years
Stock option expiration period	10 years
Weighted average fair value per stock option granted	$ 14.95	$ 11.95	$ 11.55
Total intrinsic value of stock options exercised	16	40	35
Cash received from the exercise of stock options	10	47	53
Tax benefit realized with respect to the exercise of stock options	5	13	11
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per share of the restricted stock units and performance units granted	$ 83.75	$ 68.64	$ 60.58
Total fair value of the restricted stock units and performance units vested	72	74	59
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per share of the restricted stock units and performance units granted	$ 98.46	$ 63.38	$ 64.34
Total fair value of the restricted stock units and performance units vested	$ 64	$ 70	$ 47