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, 2021	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Liability, Other Retirement Benefits, Noncurrent	$ 110	$ 97
Asset Retirement Obligation	56	37
Provision for rate refunds (1)	57	24
Other Accrued Liabilities, Current	89	88
Other Liabilities, Noncurrent	$ 312	$ 246