Postretirement Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Defined Benefit Plan Disclosure [Line Items]
Recognition of previously deferred postretirement benefit plan amounts	$ 254	$ 249	$ 761	$ 655
Recognition of previously deferred postretirement benefit plan amounts, tax	138	136	417	358
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Contributions made by the employer	$ 750		$ 1,500