Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Long-term Purchase Commitment [Table Text Block]

As of September 30, 2018, minimum payment obligations for natural gas supply commitments are approximately:

	(in millions)
Remaining three months of 2018	$	88
2019	325
2020	303
2021	219
2022	183
2023 and beyond	1,644