LEASES - Lease Expense (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Amortization of assets, included in Depreciation and amortization expense	$ 3
Interest on lease liabilities, included in Interest expense	2
Amortization of assets, included in Total operating expense	2
Interest on lease liabilities, included in Total operating expense	1
Total net lease cost	$ 8