SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT - STATEMENT OF COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Statement of Income Captions [Line Items]
Net income	$ 432	$ 421	$ 2,305	$ 947	$ 500	$ 909	$ 435	$ 518	$ 4,105	$ 2,362	$ 1,126
Total other comprehensive (loss) income									422	(140)	(133)
Pretax amount [Member]
Condensed Statement of Income Captions [Line Items]
Net income									5,368	2,585	1,146
Foreign currency translation adjustments									547	(43)	(144)
Financial instruments									(146)	(161)	64
Pension and other postretirement benefits									11	25	(38)
Total other comprehensive (loss) income									412	(179)	(118)
Total comprehensive income, after preferred dividends of subsidiaries									5,779	2,405	1,027
Income tax benefit [Member]
Condensed Statement of Income Captions [Line Items]
Net income									(1,435)	(387)	(96)
Foreign currency translation adjustments									0	0	0
Financial instruments									33	53	(21)
Pension and other postretirement benefits									1	(7)	4
Total other comprehensive (loss) income									34	46	(17)
Total comprehensive income, after preferred dividends of subsidiaries									(1,401)	(341)	(113)
Net-of-tax amount [Member]
Condensed Statement of Income Captions [Line Items]
Net income									3,933	2,198	1,050
Foreign currency translation adjustments									547	(43)	(144)
Financial instruments									(113)	(108)	43
Pension and other postretirement benefits									12	18	(34)
Total other comprehensive (loss) income									446	(133)	(135)
Total comprehensive income, after preferred dividends of subsidiaries									4,378	2,064	914
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income									3,932	2,197	1,049
Parent Company [Member] | Pretax amount [Member]
Condensed Statement of Income Captions [Line Items]
Net income									3,756	2,034	895
Foreign currency translation adjustments									547	(43)	(144)
Financial instruments									(146)	(161)	64
Pension and other postretirement benefits									11	25	(38)
Total other comprehensive (loss) income									412	(179)	(118)
Total comprehensive income, after preferred dividends of subsidiaries									4,168	1,855	777
Parent Company [Member] | Income tax benefit [Member]
Condensed Statement of Income Captions [Line Items]
Net income									176	163	154
Foreign currency translation adjustments									0	0	0
Financial instruments									33	53	(21)
Pension and other postretirement benefits									1	(7)	4
Total other comprehensive (loss) income									34	46	(17)
Total comprehensive income, after preferred dividends of subsidiaries									210	209	137
Parent Company [Member] | Net-of-tax amount [Member]
Condensed Statement of Income Captions [Line Items]
Net income									3,932	2,197	1,049
Foreign currency translation adjustments									547	(43)	(144)
Financial instruments									(113)	(108)	43
Pension and other postretirement benefits									12	18	(34)
Total other comprehensive (loss) income									446	(133)	(135)
Total comprehensive income, after preferred dividends of subsidiaries									$ 4,378	$ 2,064	$ 914