Leases
 9 Months Ended
Sep. 30, 2019
Leases [Abstract]  
Leases Leases
The Company has operating leases for corporate offices, lands for its wind and solar facilities, and certain equipment. The leases have remaining lease terms of 2 months to 18 years, some of which may include renewal and extension options. Generally, these options do not impact the lease term because the Company is not reasonably certain that it will exercise the options.
The Company subleases its former headquarters to a third-party. As the Company remains the primary obligor under the original lease, which expires in 2026, the Company continues to account for the lease as an operating lease. Sublease income is recognized on a straight-line basis over the remaining life of the sublease. As of September 30, 2019, future sublease proceeds under the sublease agreement are less than $1 million for the remaining three months of 2019 and $2 million per year for 2020 through 2026.
Supplemental balance sheet information related to leases are as follows (in millions):
Operating leases
 
Balance sheet location
 
September 30, 2019
Operating lease right-of-use assets
 
Other assets
 
$
63

Operating lease liabilities, current
 
Other current liabilities
 
(10
)
Operating lease liabilities
 
Other long-term liabilities
 
(68
)
Total operating lease liabilities
 
 
 
$
(78
)

As of September 30, 2019, maturities of operating lease liabilities were as follows (in millions):
Remainder of 2019
 
3

2020
 
9

2021
 
9

2022
 
9

2023
 
9

Thereafter
 
51

Total lease payment
 
$
90

Less imputed interest
 
(12
)
Total
 
$
78


The components of lease expense are as follows (in millions):
 
 
Three months ended
September 30, 2019
 
Nine months ended
September 30, 2019
Operating lease cost
 
$
2

 
$
6

Sublease income
 
(1
)
 
(2
)
Total lease cost
 
$
1

 
$
4

Supplemental cash flow and other information related to the Company's operating leases are as follows (in millions, except for lease term and discount rate):
 
 
Nine months ended
September 30, 2019
Operating cash flows from operating leases (1)
 
$
(7
)
Right of use assets obtained in exchange for new operating lease obligations (2)
 
$
1

Weighted average remaining lease term (years):
 
11.0

Weighted average discount rate (3):
 
3.24
%
(1) 
Represents cash paid for amounts included in the measurement of lease liabilities.
(2) 
Represents non-cash activity and, accordingly, is not reflected in the consolidated statements of cash flows.
(3) 
When an implicit rate is not readily determinable, the interest rate used to determine the present value of the future lease payments is the Company's incremental borrowing rate.
As of September 30, 2019, the Company does not have any significant leases that have not yet commenced.
As of December 31, 2018, estimated future commitments related to operating leases and land agreements were as follows (in millions):
2019
 
$
22

2020
 
21

2021
 
22

2022
 
21

2023
 
22

Thereafter
 
352

Total
 
$
460


These amounts include certain land agreements not accounted for as leases under ASC 842, which are excluded from the lessee's maturity analysis presented above.