Capital Actions (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Capital Actions
Amount	$ (99)	$ (125)
November 13, 2013 ASR | March 2013 Repurchase Program
Capital Actions
Repurchase date	Nov. 18, 2013
Amount	200
Shares repurchased	8,538,423
Shares received from forward contract settlement	1,132,495
Total shares repurchased	9,670,918
Settlement date	Mar. 05, 2014
December 10, 2013 ASR | March 2013 Repurchase Program
Capital Actions
Repurchase date	Dec. 13, 2013
Amount	456
Shares repurchased	19,084,195
Shares received from forward contract settlement	2,294,932
Total shares repurchased	21,379,127
Settlement date	Mar. 31, 2014
January 28, 2014 ASR | March 2013 Repurchase Program
Capital Actions
Repurchase date	Jan. 31, 2014
Amount	$ 99
Shares repurchased	3,950,705
Shares received from forward contract settlement	602,109
Total shares repurchased	4,552,814
Settlement date	Mar. 31, 2014