Effects of Prior Period Corrections on Annual Consolidated Statement of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended			3 Months Ended							12 Months Ended		3 Months Ended						9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013 Reported	Jun. 30, 2013 Reported	Mar. 31, 2013 Reported	Dec. 31, 2012 Reported	Sep. 30, 2012 Reported	Jun. 30, 2012 Reported	Mar. 31, 2012 Reported	Dec. 31, 2012 Reported	Dec. 31, 2011 Reported	Sep. 30, 2013 Correction	Jun. 30, 2013 Correction	Mar. 31, 2013 Correction	Dec. 31, 2012 Correction	Sep. 30, 2012 Correction	Mar. 31, 2012 Correction	Sep. 30, 2013 Correction	Dec. 31, 2012 Correction	Dec. 31, 2011 Correction
Error Corrections and Prior Period Adjustments Revision [Line Items]
Net earnings	$ 1,773	$ 1,018	$ 602	$ 542	$ 578	$ 664	$ 1,034	$ 818	$ 3,935	$ 3,094	$ 3,574	$ 1,030	$ 617	$ 574	$ 543	$ 659	$ 1,034	$ 819	$ 3,055	$ 3,547	$ (12)	$ (15)	$ (32)	$ 35	$ 5	$ (1)	$ 59	$ 39	$ 27
Deferred income tax (benefit) / provision									(64)	369	(351)								410	(351)								(41)
Other non-cash expense, net									(19)	44	82								48	81								(4)	1
Change in other current liabilities									62	(1,160)	648								(1,166)	676								6	(28)
Net cash provided by operating activities									$ 6,410	$ 3,923	$ 4,520								$ 3,923	$ 4,520