Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning of year				$ 7,625
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Dec. 31, 2018		$ 397	$ 1,281	7,625	$ 22	$ (1,492)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		0	(12)			21
Share-based compensation			30
Other			7			3
Net Income	$ 1,997			1,997
Dividends declared				(365)
Other comprehensive income (loss)	426				426
Shares acquired - share repurchase authorization						(67)
Shares acquired - share-based compensation plans						(9)
Ending Balance at Dec. 31, 2019	9,864	$ 397	1,306	9,257	448	(1,544)
Beginning Balance (in shares) at Dec. 31, 2018		162,800
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		700
Shares acquired—share repurchase authorization (in shares)		(600)
Shares acquired - share-based compensation plans (in shares)		(100)
Other (in shares)		100
Ending Balance (in shares) at Dec. 31, 2019		162,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning of year				9,255
Increase to allowance through retained earnings for ASU 2016-13, after-tax				(2)
Share-based awards		$ 0	(15)			15
Share-based compensation			31
Other			6			5
Net Income	1,216			1,216
Dividends declared				(386)
Other comprehensive income (loss)	321				321
Shares acquired - share repurchase authorization						(261)
Shares acquired - share-based compensation plans						(5)
Ending Balance at Dec. 31, 2020	10,789	$ 397	1,328	10,085	769	(1,790)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		500
Shares acquired—share repurchase authorization (in shares)		(2,500)
Shares acquired - share-based compensation plans (in shares)		(100)
Other (in shares)		100
Ending Balance (in shares) at Dec. 31, 2020		160,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning of year				10,085
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Share-based awards		$ 0	(14)			18
Share-based compensation			33
Other			9			3
Net Income	2,946			2,946
Dividends declared				(406)
Other comprehensive income (loss)	(121)				(121)
Shares acquired - share repurchase authorization						(144)
Shares acquired - share-based compensation plans						(8)
Ending Balance at Dec. 31, 2021	$ 13,105	$ 397	$ 1,356	$ 12,625	$ 648	$ (1,921)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)	415	600
Shares acquired—share repurchase authorization (in shares)		(1,200)
Shares acquired - share-based compensation plans (in shares)		(100)
Other (in shares)		100
Ending Balance (in shares) at Dec. 31, 2021		160,300