Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Minimum commitments

Minimum commitments as of December 31, 2017 consist of the following:

(millions)	Drilling, Equipment, and Purchase Obligations		Transportation and Gathering Obligations		Operating Lease  Obligations		Capital  Lease and Other Obligations(1)		Total
2018	$	636	$	215	$	44	$	74	$	969
2019	167		252		33		45		497
2020	40		247		32		42		361
2021	13		223		32		29		297
2022	8		182		33		21		244
2023 and Thereafter	32		1,355		156		124		1,667
Total	$	896	$	2,474	$	330	$	335	$	4,035

⁽¹⁾ Annual lease payments, net to our interest, exclude regular maintenance and operational costs. See Note 10. Long-Term Debt.