FAIR VALUE MEASUREMENTS - LONG-TERM DEBT (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recurring purchase price accounting fair value adjustment	$ 2	$ 3
Carrying amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed rate debt at cost	567	639
Long-term debt	569	642
Fair value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 584	$ 641