SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION Interest Income and Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Supplemental Income Statement Elements [Abstract]
Interest expense	$ 183	$ 186	$ 363	$ 373
Interest income	50	49	95	94
Capitalized interest costs	$ 9	$ 6	$ 17	$ 12