FAIR VALUE MEASUREMENTS - LONG-TERM DEBT (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recurring purchase price accounting fair value adjustment	$ 3	$ 3
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed rate debt at cost	639	956
Long-term debt	642	959
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 641	$ 959