Consolidated Condensed Statements of Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2021	$ 20,327	$ 9,762	$ 217	$ (10,673)	$ 16,749	$ 4,480	$ (208)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,377					11,377
Other comprehensive income, net of tax	121						121
Dividends on common stock	(369)					(369)
Dividends on preferred stock	(600)					(600)
Shareholder warrants exercised	253		2		251
Options exercised	27				27
Issuance of common stock and other, net of cancellations	103		1		102
Purchases of treasury stock	(2,519)			(2,519)
Ending balance at Sep. 30, 2022	28,720	9,762	220	(13,192)	17,129	14,888	(87)
Beginning balance at Jun. 30, 2022	27,830	9,762	218	(11,391)	16,914	12,462	(135)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,746					2,746
Other comprehensive income, net of tax	48						48
Dividends on common stock	(120)					(120)
Dividends on preferred stock	(200)					(200)
Shareholder warrants exercised	163		1		162
Options exercised	10				10
Issuance of common stock and other, net of cancellations	44		1		43
Purchases of treasury stock	(1,801)			(1,801)
Ending balance at Sep. 30, 2022	28,720	9,762	220	(13,192)	17,129	14,888	(87)
Beginning balance at Dec. 31, 2022	30,085	9,762	220	(13,772)	17,181	16,499	195
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,498					3,498
Other comprehensive income, net of tax	98						98
Dividends on common stock	(485)					(485)
Dividends on preferred stock	(567)					(567)
Preferred stock redemption - face value	(1,511)	(1,511)
Preferred stock redemption - premium	(151)					(151)
Preferred stock redemption value in excess of carrying value	0	36				(36)
Shareholder warrants exercised	57				57
Options exercised	13				13
Issuance of common stock and other, net of cancellations	76		1		75
Purchases of treasury stock	(1,801)			(1,801)
Ending balance at Sep. 30, 2023	29,312	8,287	221	(15,573)	17,326	18,758	293
Beginning balance at Jun. 30, 2023	29,111	8,621	221	(14,958)	17,218	17,762	247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,375					1,375
Other comprehensive income, net of tax	46						46
Dividends on common stock	(160)					(160)
Dividends on preferred stock	(177)					(177)
Preferred stock redemption - face value	(342)	(342)
Preferred stock redemption - premium	(34)					(34)
Preferred stock redemption value in excess of carrying value	0	8				(8)
Shareholder warrants exercised	54				54
Issuance of common stock and other, net of cancellations	54				54
Purchases of treasury stock	(615)			(615)
Ending balance at Sep. 30, 2023	$ 29,312	$ 8,287	$ 221	$ (15,573)	$ 17,326	$ 18,758	$ 293