Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Preferred Stock [Member]	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	AOCI Attributable to Parent [Member]	Share-based Payment Arrangement [Member] Treasury Stock
Beginning balance at Dec. 31, 2020				$ 4,322	$ 13,918	$ (1,192)	$ 1,170
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under incentive and stock compensation plans and other				(69)
Stock-based compensation plans expense				57
Net income	$ 249				249
Dividends declared on preferred stock	(5)				(5)
Dividends declared on common stock					(126)
Treasury stock acquired	(123)					(123)
Issuance of shares under incentive and stock compensation plans from treasury stock and other								$ 94
Net shares acquired related to employee incentive and stock compensation plans						(25)
Total other comprehensive loss							(906)
Ending balance at Mar. 31, 2021	$ 17,702	$ 334	$ 4	4,310	14,036	(1,246)	264
13800000 at Mar. 31, 2021		13,800
Common Shares Outstanding, beginning of period at Dec. 31, 2020			358,489
Shares Granted or Issued, Share-based Payment Arrangement [Abstract]
Treasury stock acquired	(2,400)		(2,386)
Issuance of shares under incentive and stock compensation plans and other			1,914
Return of shares under incentive and stock compensation plans to treasury stock			(500)
Common Shares Outstanding, at end of period at Mar. 31, 2021			357,517
Shares Granted or Issued, Share-based Payment Arrangement [Abstract]
Cash dividends declared per common share	$ 0.350
Cash dividends declared per preferred share	$ 375.00
Beginning balance at Dec. 31, 2021	$ 17,843			3,309	15,764	(1,740)	172
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under incentive and stock compensation plans and other				(115)
Stock-based compensation plans expense				55
Net income	445				445
Dividends declared on preferred stock	(5)				(5)
Dividends declared on common stock					(127)
Treasury stock acquired	(400)					(400)
Issuance of shares under incentive and stock compensation plans from treasury stock and other								$ 124
Net shares acquired related to employee incentive and stock compensation plans						(52)
Total other comprehensive loss							(1,871)
Ending balance at Mar. 31, 2022	$ 15,897	$ 334	$ 4	$ 3,249	$ 16,077	$ (2,068)	$ (1,699)
13800000 at Mar. 31, 2022		13,800
Common Shares Outstanding, beginning of period at Dec. 31, 2021			334,926
Shares Granted or Issued, Share-based Payment Arrangement [Abstract]
Treasury stock acquired	(5,700)		(5,682)
Issuance of shares under incentive and stock compensation plans and other			2,210
Return of shares under incentive and stock compensation plans to treasury stock			(745)
Common Shares Outstanding, at end of period at Mar. 31, 2022			330,709
Shares Granted or Issued, Share-based Payment Arrangement [Abstract]
Cash dividends declared per common share	$ 0.385
Cash dividends declared per preferred share	$ 375.00