Share-Based Compensation - Schedule of Stock Option Activity (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]
Stock Options outstanding, Weighted Average Exercise Price, Beginning Balance	$ 11.56	$ 9.26	$ 8.58
Granted, Weighted Average Exercise Price	$ 37.49	$ 27.03	$ 23.35
Exercised, Weighted Average Exercise Price	$ 8.49	$ 7.60	$ 6.31
Cancelled, Weighted Average Exercise Price	$ 25.50	$ 9.49	$ 5.88
Stock Options outstanding, Weighted Average Exercise Price, Ending Balance	$ 15.82	$ 11.56	$ 9.26
Options exercisable, Weighted Average Exercise Price	$ 10.55
Options outstanding, Weighted Average Remaining Contractual Term	5 years 4 months 24 days
Options exercisable, Weighted Average Remaining Contractual Term	4 years 1 month 6 days
Options outstanding, Aggregate Intrinsic Value	$ 1,122
Options exercisable, Aggregate Intrinsic Value	$ 947
Time Based Stock Options and SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Outstanding, Beginning Balance	19,191,000	21,739,000	24,517,000
Granted, Stock Options	2,432,000	3,174,000	644,000
Exercised, Stock Options	(4,498,000)	(5,530,000)	(3,312,000)
Cancelled, Stock Options	(316,000)	(192,000)	(110,000)
Stock Options Outstanding, Ending Balance	16,809,000	19,191,000	21,739,000
Stock Options Exercisable, Ending Balance	11,960,000
Performance Stock Options and SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Outstanding, Beginning Balance	22,051,000	24,573,000	26,009,000
Granted, Stock Options	2,432,000	3,174,000	644,000
Exercised, Stock Options	(5,843,000)	(5,128,000)	(1,732,000)
Cancelled, Stock Options	(263,000)	(568,000)	(348,000)
Stock Options Outstanding, Ending Balance	18,377,000	22,051,000	24,573,000
Stock Options Exercisable, Ending Balance	13,527,000
Total Stock Options and Stock SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Outstanding, Beginning Balance	41,242,000	46,312,000	50,526,000
Granted, Stock Options	4,864,000	6,348,000	1,288,000
Exercised, Stock Options	(10,341,000)	(10,658,000)	(5,044,000)
Cancelled, Stock Options	(579,000)	(760,000)	(458,000)
Stock Options Outstanding, Ending Balance	35,186,000	41,242,000	46,312,000
Stock Options Exercisable, Ending Balance	25,487,000