SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation allowance for deferred tax assets
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Deductions			$ (53)
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 4,183	$ 2,434	2,487
Additions Charged to Cost and Expense	1,852	1,749
Additons Charged to Other Accounts	23	0	0
Other Additions (Deductions)	0	0	0
Balance at End of Year	6,058	4,183	2,434
Reserve for Taxes, Other than Income Taxes [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Deductions	(3)
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	83	93	78
Additions Charged to Cost and Expense	13	9	16
Additons Charged to Other Accounts		0	0
Other Additions (Deductions)	(29)	(19)	(1)
Balance at End of Year	$ 64	$ 83	$ 93