Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Energy Related Inventory [Abstract]

Inventory Disclosure Table

The following summarizes the major classes of inventories included in other current assets:

millions	March 31,   2018		December 31,   2017
Oil	$	184	$	165
Natural gas	8		29
NGLs	117		122
Total inventories	$	309	$	316