SEGMENT INFORMATION - Schedule of Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 5,992	$ 5,873
Segment Balances Before Intersegment Eliminations and Consolidation Reconciling Items [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	2,797	2,684
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	3,087	2,879
Eliminations and Unallocated in Consolidation [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	108	310
United States [Member] | Segment Balances Before Intersegment Eliminations and Consolidation Reconciling Items [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	2,625	2,496
Canada [Member] | Segment Balances Before Intersegment Eliminations and Consolidation Reconciling Items [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 172	$ 188