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)	1,357			1,357
Other comprehensive income (loss), net of tax	254					254
Total comprehensive income (loss)	1,611
Dividends to shareholders	(386)			(386)
Repurchase of common shares (in shares)		(7,392,430)
Repurchase of common shares	(1,135)				(1,135)
Share-based compensation plans (in shares)		2,084,805
Share-based compensation plans	257		216		41
Ending balance (in shares) at Sep. 30, 2020		118,631,609
Ending balance at Sep. 30, 2020	6,067	$ 3	8,677	15,241	(18,370)	516
Beginning balance (in shares) at Jun. 30, 2020		120,607,501
Beginning balance at Jun. 30, 2020	6,500	$ 3	8,622	15,510	(18,029)	394
Comprehensive income (loss):
Net income (loss)	(140)			(140)
Other comprehensive income (loss), net of tax	122					122
Total comprehensive income (loss)	(18)
Dividends to shareholders	(129)			(129)
Repurchase of common shares (in shares)		(2,215,753)
Repurchase of common shares	(341)				(341)
Share-based compensation plans (in shares)		239,861
Share-based compensation plans	55		55
Ending balance (in shares) at Sep. 30, 2020		118,631,609
Ending balance at Sep. 30, 2020	6,067	$ 3	8,677	15,241	(18,370)	516
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)	2,059			2,059
Other comprehensive income (loss), net of tax	(530)					(530)
Total comprehensive income (loss)	1,529
Dividends to shareholders	(396)			(396)
Repurchase of common shares (in shares)		(6,724,301)
Repurchase of common shares	(1,624)				(1,624)
Share-based compensation plans (in shares)		2,356,275
Share-based compensation plans	331		296		35
Ending balance (in shares) at Sep. 30, 2021		112,397,587
Ending balance at Sep. 30, 2021	5,707	$ 3	9,118	16,955	(20,468)	99
Beginning balance (in shares) at Jun. 30, 2021		114,297,434
Beginning balance at Jun. 30, 2021	5,686	$ 3	9,049	16,057	(19,883)	460
Comprehensive income (loss):
Net income (loss)	1,031			1,031
Other comprehensive income (loss), net of tax	(361)					(361)
Total comprehensive income (loss)	670
Dividends to shareholders	(133)			(133)
Repurchase of common shares (in shares)		(2,236,129)
Repurchase of common shares	(586)				(586)
Share-based compensation plans (in shares)		336,282
Share-based compensation plans	70		69		1
Ending balance (in shares) at Sep. 30, 2021		112,397,587
Ending balance at Sep. 30, 2021	$ 5,707	$ 3	$ 9,118	$ 16,955	$ (20,468)	$ 99