Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets [Table Text Block]

The gross carrying amount and accumulated amortization of intangible assets, included in Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet, at December 31 are as follows:

	2021				2020
	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	(Millions)
Customer relationships	$	9,593	$	(2,448)	$	9,555	$	(2,116)
Transportation and storage capacity contracts	267		(14)		—		—
Other intangible assets	6		(2)		6		(1)
	$	9,866	$	(2,464)	$	9,561	$	(2,117)