Our leasing activities primarily consist of operating leases for shorebase offices, office and information technology equipment, employee housing, vehicles, onshore storage yards and certain rig equipment and tools. Our leases have terms ranging from one month to ten years, some of which include options to extend the lease for up to five years and/or to terminate the lease within one year.

Additionally, we are participants in four sale and leaseback arrangements with a subsidiary of GE Oil & Gas, or GE, pursuant to the 2016 sale of certain blowout preventers and related well control equipment, or Well Control Equipment, on our drillships and corresponding agreements to lease back that equipment under ten-year operating leases for approximately $26 million per year with renewal options for two successive five-year periods. At the time of the transactions with GE, the carrying value of the Well Control Equipment exceeded the aggregate proceeds received from the sale, resulting in the recognition of prepaid rent, which was being amortized over the respective terms of the leases. On January 1, 2019, as a result of the adoption of ASU 2016-02, the aggregate remaining prepaid rent balances of $3.9 million and $10.6 million, previously recorded as “Prepaid expenses and other current assets” and “Other assets,” respectively, were reclassified to a right-of-use lease asset within “Other assets” in our unaudited Condensed Consolidated Balance Sheets and continue to be amortized over the remaining terms of the leases. In connection with the sale and leaseback transactions, we also entered into a ten-year service agreement with another GE affiliate pertaining to the Well Control Equipment. Such services include management of maintenance, certification and reliability with respect to such equipment.

In applying the standard, we utilize an exemption for short-term leases whereby we do not record leases with terms of one year or less on the balance sheet. We have also made an accounting policy election to not separate lease components from non-lease components for each of our classes of underlying assets, except for subsea equipment, which includes the Well Control Equipment discussed above. At inception, the consideration for the overall Well Control Equipment arrangement was allocated between the lease and service components based on an estimation of stand-alone selling price of each component, which maximized observable inputs. The costs associated with the service portion of the agreement are accounted for separately from the cost attributable to the equipment leases based on that allocation and thus, are not included in our right-of-use lease asset or lease liability balances. The non-lease components for each of our other classes of assets generally relate to maintenance, monitoring and security services and are not separated from their respective lease components.

The lease term used for calculating our right-of-use assets and lease liabilities is determined by considering the noncancelable lease term, as well as any extension options that we are reasonably certain to exercise. The determination to include option periods is generally made by considering the activity in the region or for the rig corresponding to the respective lease, among other contract-based and market-based factors. We have used our incremental borrowing rate to discount future lease payments as the rate implicit in our leases is not readily determinable. To arrive at our incremental borrowing rate, we consider our unsecured borrowings and then adjust those rates to assume full collateralization and to factor in the individual lease term and payment structure.

Total operating lease expense for the three months ended March 31, 2019 was $9.4 million, of which $1.3 million related to short-term leases. Total operating lease expense for the three months ended March 31, 2018 was $7.6 million.

Supplemental information related to leases is as follows (in thousands, except weighted-average data):

	Three Months Ended March 31, 2019
Operating cash flows used for operating leases	$	11,302
Right-of-use assets obtained in exchange for lease liabilities		714
Weighted-average remaining lease term	7.0 years
Weighted-average discount rate		9.24	%

Future minimum rental payments under noncancelable operating leases as of December 31, 2018 were as follows (in thousands):

2019	$	28,373
2020		27,144
2021		26,565
2022		26,281
2023		26,280
Thereafter		64,062
Total lease payments	$	198,705

Maturities of lease liabilities as of March 31, 2019 are as follows (in thousands):

2019 (excluding three months ended March 31, 2019)	$	23,739
2020		27,865
2021		26,545
2022		26,296
2023		26,280
2024		26,352
Thereafter		37,710
Total lease payments		194,787
Less: interest		(51,737	)
Total lease liability	$	143,050
Amounts recognized in unaudited Condensed Consolidated Balance Sheet:
Accrued liabilities	$	29,334
Other liabilities		113,716
Total operating lease liability	$	143,050

Operating lease assets, including prepaid rent balances related to the GE transaction, totaling $157.0 million are included in “Other assets” in our unaudited Condensed Consolidated Balance Sheets as of March 31, 2019.

As of March 31, 2019, we have three additional operating leases for mooring equipment to be used on our rigs that have not yet commenced. These agreements provide for fixed lease payments of approximately $12 million to be paid over each of the respective lease terms, or an aggregate of approximately $36 million. These leases are expected to commence in April, May and September of 2019, and each is expected to have a lease term of approximately ten years.