FAIR VALUE MEASUREMENTS (Details) - Recurring basis - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Fair value of assets and liabilities measured on recurring basis
Marketable debt securities-noncurrent	$ 60	$ 59
Investments	60	59
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair value of assets and liabilities measured on recurring basis
Marketable debt securities-noncurrent	25	24
Investments	$ 25	$ 24
Estimated fair value of the long-term debt instrument as a percentage of carrying value	99.10%	96.20%
Significant Other Observable Inputs (Level 2)
Fair value of assets and liabilities measured on recurring basis
Marketable debt securities-noncurrent	$ 35	$ 35
Investments	$ 35	$ 35