Commodity Inventories (Tables)

12 Months Ended

Dec. 31, 2018

Energy Related Inventory [Abstract]

Inventory Disclosure Table

The following summarizes the major classes of commodity inventories included in other current assets at December 31:

millions	2018		2017
Oil	$	139	$	165
Natural gas	18		29
NGLs	78		122
Total commodity inventories	$	235	$	316