Consolidated Statements Of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]
Cumulative effect of new accounting principle in period of adoption	$ 26			$ 26	$ 0
Adjusted beginning balance	28,567		$ 9,536	20,014	(986)
Balance at Dec. 31, 2018	28,541	$ 3	9,536	19,988	(986)
Balance (in shares) at Dec. 31, 2018		257.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,551			1,551
Other comprehensive income (loss)	363				363
Repurchase and retirement of common stock, value	(294)	$ 0	(71)	(223)
Repurchase and retirement of common stock, shares		(1.1)
Dividends and dividend equivalents	(206)			(206)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		1.1
Issuance of common stock under employee stock plans, net of related tax benefits	69		69
Convertible debenture repurchases and conversions	(52)		(52)
Balance at Mar. 31, 2019	29,998	$ 3	9,482	21,136	(623)
Balance (in shares) at Mar. 31, 2019		257.4
Balance at Dec. 31, 2018	28,541	$ 3	9,536	19,988	(986)
Balance (in shares) at Dec. 31, 2018		257.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,873
Other comprehensive income (loss)	687
Repurchase and retirement of common stock, value	$ (1,396)
Repurchase and retirement of common stock, shares	(5.2)
Balance at Sep. 30, 2019	$ 31,332	$ 3	9,524	22,104	(299)
Balance (in shares) at Sep. 30, 2019		253.8
Balance at Mar. 31, 2019	29,998	$ 3	9,482	21,136	(623)
Balance (in shares) at Mar. 31, 2019		257.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,139			1,139
Other comprehensive income (loss)	240				240
Repurchase and retirement of common stock, value	(458)	$ 0	(70)	(388)
Repurchase and retirement of common stock, shares		(1.7)
Dividends and dividend equivalents	(208)			(208)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		0.2
Issuance of common stock under employee stock plans, net of related tax benefits	91		91
Convertible debenture repurchases and conversions	(9)		(9)
Balance at Jun. 30, 2019	30,793	$ 3	9,494	21,679	(383)
Balance (in shares) at Jun. 30, 2019		255.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,183			1,183
Other comprehensive income (loss)	84				84
Repurchase and retirement of common stock, value	(644)	$ 0	(90)	(554)
Repurchase and retirement of common stock, shares		(2.4)
Dividends and dividend equivalents	(204)			(204)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		0.3
Issuance of common stock under employee stock plans, net of related tax benefits	120		120
Balance at Sep. 30, 2019	31,332	$ 3	9,524	22,104	(299)
Balance (in shares) at Sep. 30, 2019		253.8
Cumulative effect of new accounting principle in period of adoption	(35)			(35)
Adjusted beginning balance	31,693		9,448	22,538	(296)
Balance at Dec. 31, 2019	31,728	$ 3	9,448	22,573	(296)
Balance (in shares) at Dec. 31, 2019		252.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,523			1,523
Other comprehensive income (loss)	(712)				(712)
Repurchase and retirement of common stock, value	(529)		(71)	(458)
Repurchase and retirement of common stock, shares		(1.9)
Dividends and dividend equivalents	(243)			(243)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		1.0
Issuance of common stock under employee stock plans, net of related tax benefits	3		3
Convertible debenture repurchases and conversions	(42)		(42)
Balance at Mar. 31, 2020	31,693	$ 3	9,338	23,360	(1,008)
Balance (in shares) at Mar. 31, 2020		252.0
Balance at Dec. 31, 2019	31,728	$ 3	9,448	22,573	(296)
Balance (in shares) at Dec. 31, 2019		252.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,021
Other comprehensive income (loss)	184
Repurchase and retirement of common stock, value	$ (1,342)
Repurchase and retirement of common stock, shares	(5.0)
Balance at Sep. 30, 2020	$ 33,921	$ 3	9,352	24,678	(112)
Balance (in shares) at Sep. 30, 2020		249.4
Balance at Mar. 31, 2020	31,693	$ 3	9,338	23,360	(1,008)
Balance (in shares) at Mar. 31, 2020		252.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,276			2,276
Other comprehensive income (loss)	754				754
Repurchase and retirement of common stock, value	(55)		(9)	(46)
Repurchase and retirement of common stock, shares		(0.2)
Dividends and dividend equivalents	(244)			(244)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		0.3
Issuance of common stock under employee stock plans, net of related tax benefits	113		113
Convertible debenture repurchases and conversions	(82)		(82)
Balance at Jun. 30, 2020	34,455	$ 3	9,360	25,346	(254)
Balance (in shares) at Jun. 30, 2020		252.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	222			222
Other comprehensive income (loss)	142				142
Repurchase and retirement of common stock, value	(758)		(106)	(652)
Repurchase and retirement of common stock, shares		(2.9)
Dividends and dividend equivalents	(238)			(238)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		0.2
Issuance of common stock under employee stock plans, net of related tax benefits	98		98
Balance at Sep. 30, 2020	$ 33,921	$ 3	$ 9,352	$ 24,678	$ (112)
Balance (in shares) at Sep. 30, 2020		249.4