Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies Inventories (Tables)

12 Months Ended

Dec. 31, 2019

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

The following table presents a summary of inventories.

	Years ended December 31,
	2019		2018
	(Millions)
Material, supplies and other	$	36	$	46
Commodity production in storage	5		2
	$	41	$	48