Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

The following table shows the future minimum lease payments under operating and capital leases for continuing operations together with the present value of the net minimum lease payments under capital leases as of December 31, 2017 for 2018 through 2022 and thereafter (in millions):



	Future Commitments for
December 31,	Capital Leases			Operating Leases
2018	$	2		$	58
2019	1			58
2020	1			58
2021	1			59
2022	1			58
Thereafter	12			644
Total	$	18		$	935
Less: Imputed interest	(10		)
Present value of total minimum lease payments	$	8

Electricity Purchase Contract Commitment

The following table shows the future minimum commitments for continuing operations under these contracts as of December 31, 2017 for 2018 through 2022 and thereafter as well as actual purchases under these contracts for the years ended December 31, 2017, 2016, and 2015 (in millions):



Actual purchases during the year ended December 31,	Electricity Purchase Contracts		Fuel Purchase Contracts		Other Purchase Contracts
2015	$	545	$	1,262	$	1,833
2016	420		1,790		817
2017	747		1,619		1,945
Future commitments for the year ending December 31,
2018	$	581	$	1,759	$	1,488
2019	508		1,051		931
2020	440		591		470
2021	469		538		234
2022	438		454		547
Thereafter	2,065		1,466		1,314
Total	$	4,501	$	5,859	$	4,984