LEASES - Right-of-use Assets and Right-of-use Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
Right-of-use assets included in:
Other non-current assets	$ 263	$ 302
Lease liabilities included in:
Accrued and other current liabilities	49
Other non-current liabilities	235
Total lease liabilities	$ 284	$ 302