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			16
Other			3			1
Net Income (Loss)	$ (317)			(317)
Dividends declared				(193)
Other comprehensive income (loss)	149				149
Shares acquired - share repurchase authorization						(256)
Shares acquired - share-based compensation plans						(3)
Ending Balance at Jun. 30, 2020	9,258	$ 397	1,309	8,745	597	(1,790)
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 Jun. 30, 2020		160.8
Dividends declared per common share		$ 1.20
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Mar. 31, 2020		$ 397	1,300	7,932	204	(1,791)	7,932
Share-based awards		0	0			1
Share-based compensation			7
Other			2			0
Net Income (Loss)	909			909
Dividends declared				(96)
Other comprehensive income (loss)	393				393
Shares acquired - share repurchase authorization						0
Shares acquired - share-based compensation plans						0
Ending Balance at Jun. 30, 2020	9,258	$ 397	1,309	8,745	597	(1,790)
Beginning Balance (in shares) at Mar. 31, 2020		160.8
Share-based awards (in shares)		0.0
Shares acquired - share repurchase authorization (in shares)		0.0
Ending Balance (in shares) at Jun. 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	(14)			15
Share-based compensation			17
Other			3			1
Net Income (Loss)	1,323			1,323
Dividends declared				(203)
Other comprehensive income (loss)	(38)				(38)
Shares acquired - share repurchase authorization						(28)
Shares acquired - share-based compensation plans						(7)
Ending Balance at Jun. 30, 2021	11,858	$ 397	1,334	11,205	731	(1,809)
Beginning Balance (in shares) at Dec. 31, 2020		160.9
Share-based awards (in shares)		0.5
Shares acquired - share repurchase authorization (in shares)		(0.3)
Ending Balance (in shares) at Jun. 30, 2021		161.1
Dividends declared per common share		$ 1.26
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Mar. 31, 2021		$ 397	1,322	10,603	625	(1,809)	$ 10,603
Share-based awards		0	2			3
Share-based compensation			8
Other			2			1
Net Income (Loss)	703			703
Dividends declared				(101)
Other comprehensive income (loss)	106				106
Shares acquired - share repurchase authorization						0
Shares acquired - share-based compensation plans						(4)
Ending Balance at Jun. 30, 2021	$ 11,858	$ 397	$ 1,334	$ 11,205	$ 731	$ (1,809)
Beginning Balance (in shares) at Mar. 31, 2021		161.0
Share-based awards (in shares)		0.1
Shares acquired - share repurchase authorization (in shares)		0.0
Ending Balance (in shares) at Jun. 30, 2021		161.1
Dividends declared per common share		$ 0.63