SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for loss on receivables:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 79	$ 96	$ 118
Acquired/(Disposed) Balances	0	0	0
Charged (Credited) to Costs and Expenses	(1)	36	20
Charged to Other Accounts	0	(29)	(10)
Deductions or Write-offs	(9)	(24)	(32)
Balance at End of Period	69	79	96
Deferred tax asset valuation allowance:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	54	49	49
Acquired/(Disposed) Balances	0	0	0
Charged (Credited) to Costs and Expenses	9	(5)	0
Charged to Other Accounts	0	0	0
Deductions or Write-offs	0	0	0
Balance at End of Period	$ 45	$ 54	$ 49