INCOME TAXES Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Deferred income tax provision (benefit), net		$ 163	$ 295	$ 3
Income tax payments, net of refunds		195	122
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 2	2
Investment tax credit		$ 6	$ 29
Effective income tax rate reconciliation, at federal statutory income tax rate, percent		21.00%		35.00%
Tax Cuts and Jobs Act of 2017, Income tax expense benefit, incomplete accounting, provisional amount				$ 1,220
Tax Cuts and Jobs Act of 2017, Income tax expense benefit, incomplete accounting, provisional amount, remeasurement of U.S. deferred taxes				1,454
Tax Cuts and Jobs Act of 2017, Income tax expense benefit, incomplete accounting, provisional amount, transition tax				231
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Measurement Period Adjustment, Income Tax Expense Benefit, Transition Tax	$ 25
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Measurement Period Adjustment, Impact on Effective Tax Rate, Transition Tax	4.50%
Tax Cuts and Jobs Act, Incomplete Accounting, Provisional Amount, Total Income Tax Expense Benefit, Transitional Tax		$ 206
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Measurement Period Adjustment, Income Tax Expense Benefit	$ (36)
Tax Cuts and Jobs Act, Change In Tax Rate, Deferred Tax Asset, Income Tax Expense	$ 11
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Measurement Period Adjustment, Impact on Effective Tax Rate, Change In Tax Rate, Deferred Tax Asset	2.00%
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Amount, Decrease In Deferred Tax Liabilities, Tax Rate Change		1,462		1,451
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Amount, Total Income Tax Expense Benefit, Change In Tax Rate		$ 1,462
Tax Cuts and Jobs Act of 2017, Change in tax rate, income tax expense benefit, incomplete accounting, provisional amount				1,451
Tax Cuts and Jobs Act of 2017, Increase decrease in valuation allowance for deferred tax assets, incomplete accounting, provisional amount				$ 3