CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Common Shares	Additional Paid-In Capital	Retained Earnings	Treasury Shares	Accumulated Other  Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Retained Earnings
Beginning balance (in shares) at Dec. 31, 2019		123,939,234
Beginning balance at Dec. 31, 2019	$ 5,729	$ 3	$ 8,461	$ 14,279	$ (17,276)	$ 262
Beginning balance (Current expected credit losses guidance) at Dec. 31, 2019							$ (9)	$ (9)
Comprehensive income (loss):
Net income (loss)	1,497			1,497
Other comprehensive income (loss), net of tax	132					132
Total comprehensive income	1,629
Dividends to shareholders	(257)			(257)
Repurchase of common shares (in shares)		(5,176,677)
Repurchase of common shares	(794)				(794)
Share-based compensation plans (in shares)		1,844,944
Share-based compensation plans	202		161		41
Ending balance (in shares) at Jun. 30, 2020		120,607,501
Ending balance at Jun. 30, 2020	6,500	$ 3	8,622	15,510	(18,029)	394
Beginning balance (in shares) at Mar. 31, 2020		122,334,887
Beginning balance at Mar. 31, 2020	6,693	$ 3	8,578	16,180	(17,773)	(295)
Comprehensive income (loss):
Net income (loss)	(539)			(539)
Other comprehensive income (loss), net of tax	689					689
Total comprehensive income	150
Dividends to shareholders	(131)			(131)
Repurchase of common shares (in shares)		(1,794,058)
Repurchase of common shares	(257)				(257)
Share-based compensation plans (in shares)		66,672
Share-based compensation plans	45		44		1
Ending balance (in shares) at Jun. 30, 2020		120,607,501
Ending balance at Jun. 30, 2020	6,500	$ 3	8,622	15,510	(18,029)	394
Beginning balance (in shares) at Dec. 31, 2020		116,765,613
Beginning balance at Dec. 31, 2020	5,867	$ 3	8,822	15,292	(18,879)	629
Comprehensive income (loss):
Net income (loss)	1,028			1,028
Other comprehensive income (loss), net of tax	(169)					(169)
Total comprehensive income	859
Dividends to shareholders	(263)			(263)
Repurchase of common shares (in shares)		(4,488,172)
Repurchase of common shares	(1,038)				(1,038)
Share-based compensation plans (in shares)		2,019,993
Share-based compensation plans	261		227		34
Ending balance (in shares) at Jun. 30, 2021		114,297,434
Ending balance at Jun. 30, 2021	5,686	$ 3	9,049	16,057	(19,883)	460
Beginning balance (in shares) at Mar. 31, 2021		115,988,271
Beginning balance at Mar. 31, 2021	5,502	$ 3	8,982	15,600	(19,400)	317
Comprehensive income (loss):
Net income (loss)	591			591
Other comprehensive income (loss), net of tax	143					143
Total comprehensive income	734
Dividends to shareholders	(134)			(134)
Repurchase of common shares (in shares)		(1,898,474)
Repurchase of common shares	(484)				(484)
Share-based compensation plans (in shares)		207,637
Share-based compensation plans	68		67		1
Ending balance (in shares) at Jun. 30, 2021		114,297,434
Ending balance at Jun. 30, 2021	$ 5,686	$ 3	$ 9,049	$ 16,057	$ (19,883)	$ 460