Consolidated Statements of Changes in Total Equity - USD ($) $ in Millions	Total	Adjustment upon Adoption		Shareholders’ Equity	Shareholders’ Equity Adjustment upon Adoption		Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss)	Retained Earnings	Retained Earnings Adjustment upon Adoption		Treasury Stock	Other Non- controlling Interests
Balance at Dec. 31, 2018	$ 41,035	$ (15)		$ 41,028	$ (15)		$ 4	$ 27,751	$ (1,711)	$ 15,088	$ (15)		$ (104)	$ 7
Changes in Total Equity
Effect of issuing stock for employee benefit plans	262			262				364					(102)
Other comprehensive income (loss)	853			853					853
Net income	4,128			4,127						4,127				1
Common dividends declared	(15)			(15)						(15)
Repurchase of common stock	(1,544)			(1,544)									(1,544)
Other transactions impacting noncontrolling interests	(5)													(5)
Balance at Sep. 30, 2019	44,699			44,696			4	28,115	(858)	19,185			(1,750)	3
Balance at Dec. 31, 2018	37
Change in Redeemable Noncontrolling Interests
Other comprehensive income (loss)	(3)
Net income	8
Other transactions impacting noncontrolling interests	(8)
Balance at Sep. 30, 2019	$ 34
Change in Redeemable Noncontrolling Interests
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Balance at Jun. 30, 2019	$ 43,818			43,815			4	27,891	(965)	17,834			(949)	3
Changes in Total Equity
Effect of issuing stock for employee benefit plans	99			99				224					(125)
Other comprehensive income (loss)	107			107					107
Net income	1,351			1,351						1,351
Repurchase of common stock	(676)			(676)									(676)
Other transactions impacting noncontrolling interests
Balance at Sep. 30, 2019	44,699			44,696			4	28,115	(858)	19,185			(1,750)	3
Balance at Jun. 30, 2019	31
Change in Redeemable Noncontrolling Interests
Other comprehensive income (loss)	1
Net income	3
Other transactions impacting noncontrolling interests	(1)
Balance at Sep. 30, 2019	34
Balance at Dec. 31, 2019	45,344	$ (30)	[1]	45,338	$ (30)	[1]	4	28,306	(941)	20,162	$ (30)	[1]	(2,193)	6
Changes in Total Equity
Effect of issuing stock for employee benefit plans	385			385				471					(86)
Other comprehensive income (loss)	400			400					400
Net income	4,335			4,323						4,323				12
Common dividends declared	(15)			(15)						(15)
Repurchase of common stock	(2,369)			(2,369)									(2,369)
Other transactions impacting noncontrolling interests	(11)													(11)
Balance at Sep. 30, 2020	48,039			48,032			4	28,777	(541)	24,440			(4,648)	7
Balance at Dec. 31, 2019	35
Change in Redeemable Noncontrolling Interests
Other comprehensive income (loss)	(10)
Net income	12
Other transactions impacting noncontrolling interests	22
Balance at Sep. 30, 2020	$ 59
Change in Redeemable Noncontrolling Interests
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Balance at Jun. 30, 2020	$ 47,371			47,366			4	28,699	(788)	23,052			(3,601)	5
Changes in Total Equity
Effect of issuing stock for employee benefit plans	76			76				78					(2)
Other comprehensive income (loss)	247			247					247
Net income	1,394			1,388						1,388				6
Repurchase of common stock	(1,045)			(1,045)									(1,045)
Other transactions impacting noncontrolling interests	(4)			0										(4)
Balance at Sep. 30, 2020	48,039			$ 48,032			$ 4	$ 28,777	$ (541)	$ 24,440			$ (4,648)	$ 7
Balance at Jun. 30, 2020	34
Change in Redeemable Noncontrolling Interests
Other comprehensive income (loss)	(4)
Net income	4
Other transactions impacting noncontrolling interests	25
Balance at Sep. 30, 2020	$ 59

[1] See Note 3 for further information about the Company's adoption of new credit loss guidance (ASU 2016-13).