Management records a right-of-use asset and lease liability for several types of operating leases, including land and buildings, alumina refinery process control technology, plant equipment, vehicles, and computer equipment. The leases have remaining terms of one to 38 years. The discount rate applied to these leases is the Company’s incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments, unless there is a rate implicit in the lease agreement. The Company does not have material financing leases.

	Second quarter ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Costs from operating leases	$	20	$	20	$	38	$	39
Variable lease payments	$	1	$	5	$	5	$	8
Short-term rental expense	$	—	$	1	$	1	$	4

The weighted average lease term and weighted average discount rate as of June 30, 2020 and December 31, 2019 were as follows:

	June 30, 2020		December 31, 2019
Weighted average lease term for operating leases (years)		4.3		4.6
Weighted average discount rate for operating leases	5.3%		5.4%

The following represents the aggregate right-of use assets and related lease obligations recognized in the Consolidated Balance Sheet at:

	June 30, 2020		December 31, 2019
Properties, plants and equipment, net	$	141	$	154
Other current liabilities	$	58	$	61
Other noncurrent liabilities and deferred credits		90		100
Total operating lease liabilities	$	148	$	161

New leases of $18 and $25 were added during the three and six months ended June 30, 2020, respectively.

The future cash flows related to the operating lease obligations as of June 30, 2020 were as follows:

2020 (excluding the six months ended June 30)	$	36
2021		58
2022		27
2023		17
2024		9
Thereafter		24
Total lease payments (undiscounted)		171
Less: discount to net present value		(23	)
Total	$	148