Contingencies and Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Operating Leases Commitments

The aggregate undiscounted commitments under our gathering, processing and transportation agreements, excluding any reimbursement from working interest and royalty interest owners, credits for third-party volumes or future costs under cost-of-service agreements, are presented below:

	December 31, 2017
	($ in millions)
2018	$	1,079
2019	1,051
2020	979
2021	883
2022	771
2023 – 2035	4,404
Total	$	9,167

The aggregate undiscounted minimum future lease payments are presented below:

	December 31, 2017
	($ in millions)
2018	$	6
2019	5
2020	2
2021	1
Total	$	14

As of December 31, 2017, the aggregate undiscounted minimum future payments under these drilling service commitments were approximately $23 million.

Gathering, Processing and Transportation Commitments

The aggregate undiscounted commitments under our gathering, processing and transportation agreements, excluding any reimbursement from working interest and royalty interest owners, credits for third-party volumes or future costs under cost-of-service agreements, are presented below:

	December 31, 2017
	($ in millions)
2018	$	1,079
2019	1,051
2020	979
2021	883
2022	771
2023 – 2035	4,404
Total	$	9,167

The aggregate undiscounted minimum future lease payments are presented below:

	December 31, 2017
	($ in millions)
2018	$	6
2019	5
2020	2
2021	1
Total	$	14

As of December 31, 2017, the aggregate undiscounted minimum future payments under these drilling service commitments were approximately $23 million.

Drilling Contracts Commitments

The aggregate undiscounted commitments under our gathering, processing and transportation agreements, excluding any reimbursement from working interest and royalty interest owners, credits for third-party volumes or future costs under cost-of-service agreements, are presented below:

	December 31, 2017
	($ in millions)
2018	$	1,079
2019	1,051
2020	979
2021	883
2022	771
2023 – 2035	4,404
Total	$	9,167

The aggregate undiscounted minimum future lease payments are presented below:

	December 31, 2017
	($ in millions)
2018	$	6
2019	5
2020	2
2021	1
Total	$	14

As of December 31, 2017, the aggregate undiscounted minimum future payments under these drilling service commitments were approximately $23 million.