SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Summary of Significant Accounting Policies - Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Liabilities, Current [Abstract]
Accrued Capital Expenditures	$ 21	$ 15	$ 13
Accrued Property Tax	5	9
Customer advances and deposits	29	32
Other current liabilities	$ 55	$ 56