SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)	$ (69)
Tax Cuts and Jobs Act of 2017, change in deferred tax asset valuation allowance	44	$ 1,100
Tax Cuts and Jobs Act of 2017, Tax Credit Carryforwards, Alternative Minimum Tax		371
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	4,507	4,575	$ 6,058
Other Additions (Deductions)	50	(345)	(1,484)
Additons Charged to Other Accounts	19	8	1
SEC Schedule, 12-09, Valuation Allowances and Reserves, Period Increase (Decrease)	0
Balance at End of Year	4,576	4,507	4,575
Reserve for Taxes, Other than Income Taxes [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	62	58	64
Other Additions (Deductions)	0	7	(2)
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	0		0
SEC Schedule, 12-09, Valuation Allowance and Reserves, Deduction, Other	(4)	(2)	(4)
Balance at End of Year	58	$ 62	$ 58
Foreign Tax Credits
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)	(208)
Net Operating Losses
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance, increase (decrease)	$ (98)