Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments And Contingencies Disclosure [Abstract]

Schedule of Long-term Commitments

The following is a schedule of future payments under minimum lease payments with non-cancelable lease terms in excess of one year and other net purchase obligations/commitments at December 31, 2018:

			Capital		Fuel and Gas		Long-term Service		Operating		Demand Side
(millions)	Transportation		Projects		Supply		Agreements		Leases		Management		Total
Year ended December 31:
2019	$	194	$	298	$	257	$	7	$	2	$	5	$	763
2020		175		89		106		6		2		1		379
2021		141		33		3		6		2		0		185
2022		133		8		3		7		2		0		153
2023		108		2		1		11		2		0		124
Thereafter		1,013		6		0		78		34		0		1,131
Total future minimum payments	$	1,764	$	436	$	370	$	115	$	44	$	6	$	2,735