BENEFITS Benefits - Fair Value of Assets by Category (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Fair Value of Plan Assets		$ 118	$ 114
Cash and Cash Equivalents
Defined Benefit Plan, Fair Value of Plan Assets		3	3
Mutual Fund
Defined Benefit Plan, Fair Value of Plan Assets	[1]	$ 115	$ 111

[1] This fund of funds invests primarily in a diversified portfolio of equity, fixed income and short-term mutual funds. As of December 31, 2015, the fund was primarily comprised of 36% equities, 54% fixed income securities and 10% cash. As of December 31, 2014, the fund was primarily comprised of 38% equities, 52% fixed income securities, and 10% cash.