ESTIMATES, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND BALANCE SHEET DETAIL Estimates, Significant Accounting Policies and Balance Sheet Detail - Other Non-Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Liability, Other Retirement Benefits, Noncurrent	$ 103	$ 117
Asset Retirement Obligation	30	26
Other Accrued Liabilities, Current	88	90
Other Liabilities, Noncurrent	$ 221	$ 233