LEASES - Balance Sheet Components (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Assets
Right of Use Assets	$ 43	$ 46
Finance lease assets	30	33
Total leased assets	73	79
Current
Operating	16	14
Finance	2	2
Noncurrent
Operating	27	32
Finance	18	21
Total lease liabilities	$ 63	$ 69
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Plants, Properties and Equipment, net	Plants, Properties and Equipment, net
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Notes payable and current maturities of long-term debt	Notes payable and current maturities of long-term debt
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term Debt and Lease Obligation	Long-term Debt and Lease Obligation
Finance lease, accumulated amortization	$ 13	$ 10