Recent Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in Total Costs and Operating Expenses (principally SG&A Expenses)	$ 5,067	$ 4,145
Decrease in Operating Income	(786)	(620)
Increase in Other Income (Expense)	(152)	(117)
Accounts receivable, less allowances	3,990		$ 3,871	$ 3,879
Inventories	2,891		2,719	2,971
Other current assets	1,217		1,100	804
Other Assets	1,178		1,150	1,227
Contract liabilities	909		805	0
Deferred Revenue	0		0	719
Other accrued expenses	1,352		1,695	1,848
Deferred Income Taxes	2,606		2,711	2,766
Other Long-term Liabilities	2,657		2,623	2,569
Long-term Obligations	18,122		18,870	18,873
Retained earnings	16,542		16,032	15,914
Accumulated other comprehensive items	(2,042)		(2,091)	$ (2,003)
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in Total Costs and Operating Expenses (principally SG&A Expenses)		2
Decrease in Operating Income		2
Increase in Other Income (Expense)		$ 2
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	(280)
Other current assets	$ 344
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			296
Contract liabilities			805
Deferred Revenue			(719)
Other accrued expenses			(153)
Other Long-term Liabilities			54
Retained earnings			$ 49