Subsequent Events - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jan. 31, 2014 Subsequent Event [Member]	Jan. 31, 2014 Minimum [Member] Subsequent Event [Member]	Jan. 31, 2014 Maximum [Member] Subsequent Event [Member]
Subsequent Event [Line Items]
Restructuring-related charges	$ 782	$ 172	$ 281		$ 90	$ 110
Restructuring-related charges after tax					$ 60	$ 70
Restructuring-related charges, per diluted shares				$ 0.06