Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common equities	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock	Previously Reported Retained Earnings
Increase to allowance through retained earnings for ASU 2016-13, after-tax				$ (2)
Beginning Balance at Dec. 31, 2019		$ 397	$ 1,306	9,255	$ 448	$ (1,544)	$ 9,257
Share-based awards		0	(16)			12
Share-based compensation			24
Other			4			3
Net Income	$ 167			167
Dividends declared				(290)
Other comprehensive income (loss)	238				238
Shares acquired - share repurchase authorization						(256)
Shares acquired - share-based compensation plans						(3)
Ending Balance at Sep. 30, 2020	9,745	$ 397	1,318	9,132	686	(1,788)
Beginning Balance (in shares) at Dec. 31, 2019		162.9
Share-based awards (in shares)		0.4
Shares acquired - share repurchase authorization (in shares)		(2.5)
Ending Balance (in shares) at Sep. 30, 2020		160.8
Dividends declared per common share		$ 1.80
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Jun. 30, 2020		$ 397	1,309	8,745	597	(1,790)	8,745
Share-based awards		0	0			0
Share-based compensation			8
Other			1			2
Net Income	484			484
Dividends declared				(97)
Other comprehensive income (loss)	89				89
Shares acquired - share repurchase authorization						0
Shares acquired - share-based compensation plans						0
Ending Balance at Sep. 30, 2020	9,745	$ 397	1,318	9,132	686	(1,788)
Beginning Balance (in shares) at Jun. 30, 2020		160.8
Share-based awards (in shares)		0.0
Shares acquired - share repurchase authorization (in shares)		0.0
Ending Balance (in shares) at Sep. 30, 2020		160.8
Dividends declared per common share		$ 0.60
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Dec. 31, 2020	10,789	$ 397	1,328	10,085	769	(1,790)	10,085
Share-based awards		0	(13)			16
Share-based compensation			25
Other			4			1
Net Income	1,476			1,476
Dividends declared				(304)
Other comprehensive income (loss)	(106)				(106)
Shares acquired - share repurchase authorization						(40)
Shares acquired - share-based compensation plans						(7)
Ending Balance at Sep. 30, 2021	11,841	$ 397	1,344	11,257	663	(1,820)
Beginning Balance (in shares) at Dec. 31, 2020		160.9
Share-based awards (in shares)		0.6
Shares acquired - share repurchase authorization (in shares)		(0.4)
Ending Balance (in shares) at Sep. 30, 2021		161.1
Dividends declared per common share		$ 1.89
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Jun. 30, 2021		$ 397	1,334	11,205	731	(1,809)	$ 11,205
Share-based awards		0	1			1
Share-based compensation			8
Other			1			0
Net Income	153			153
Dividends declared				(101)
Other comprehensive income (loss)	(68)				(68)
Shares acquired - share repurchase authorization						(12)
Shares acquired - share-based compensation plans						0
Ending Balance at Sep. 30, 2021	$ 11,841	$ 397	$ 1,344	$ 11,257	$ 663	$ (1,820)
Beginning Balance (in shares) at Jun. 30, 2021		161.1
Share-based awards (in shares)		0.1
Shares acquired - share repurchase authorization (in shares)		(0.1)
Ending Balance (in shares) at Sep. 30, 2021		161.1
Dividends declared per common share		$ 0.63