Recent Accounting Pronouncements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (Decrease) in Total Costs and Operating Expenses (principally Selling, General and Administrative Expenses)	$ 20,575	$ 17,958	$ 15,816
(Decrease) Increase in Operating Income	3,783	2,960	2,458
Increase (Decrease) in Other Income (Expense)	(521)	(531)	(434)
Accounts receivable, less allowances	4,136	3,879		$ 3,871
Inventories	3,005	2,971		2,719
Other current assets	1,381	1,236		1,465
Other Assets	1,117	1,227		1,168
Contract liabilities	809	0		736
Deferred revenue	0	719		0
Other accrued expenses	1,470	1,848		1,695
Deferred Income Taxes	2,265	2,766		2,711
Other Long-term Liabilities	2,515	2,569		2,643
Long-term Obligations	17,719	18,873		18,870
Retained earnings	18,696	15,914		16,032
Accumulated other comprehensive items	(2,498)	(2,003)		(2,091)
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (Decrease) in Total Costs and Operating Expenses (principally Selling, General and Administrative Expenses)		8	(9)
(Decrease) Increase in Operating Income		(8)	9
Increase (Decrease) in Other Income (Expense)		$ 8	$ (9)
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings				(1)
Accumulated other comprehensive items				1
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets				(77)
Deferred Income Taxes				(57)
Retained earnings				(20)
Accounting Standards Update 2017-12 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term Obligations				(3)
Retained earnings				3
Accounting Standard Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Income Taxes				2
Retained earnings				87
Accumulated other comprehensive items				(89)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Inventories	(357)
Other current assets	$ 359
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, less allowances				(8)
Inventories				(252)
Other current assets				229
Other Assets				18
Contract liabilities				736
Deferred revenue				(719)
Other accrued expenses				(153)
Other Long-term Liabilities				74
Retained earnings				$ 49