Summary of Significant Accounting Policies - Schedule of Impact of Adoption (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net earnings	$ 3,934	$ 3,764	$ 12,255	$ 12,013
Sales to customers	20,348	$ 19,650	61,187	$ 56,255
Assets	155,703		155,703		$ 157,303
Liabilities	91,077		91,077		97,143
Equity	64,626		64,626		$ 60,160
Balance without adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net earnings	3,953		12,241
Sales to customers	20,370		61,169
Assets	155,727		155,727
Liabilities	91,070		91,070
Equity	64,657		64,657
Accounting Standards Update 2014-09 | Effect of change
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net earnings	19		(14)
Sales to customers	22		(18)
Assets	24		24
Liabilities	(7)		(7)
Equity	$ 31		$ 31