We enter into various arrangements (or leases) that convey the rights to use and control identified underlying assets for a period of time in exchange for consideration. We lease various manufacturing facilities and equipment. In addition, our principal German operating subsidiary leases the land under its Leverkusen TiO₂ production facility pursuant to a lease with Bayer AG that expires in 2050. The Leverkusen facility itself, which we own and which represents approximately one-third of our current TiO₂ production capacity, is located within Bayer’s extensive manufacturing complex. From time to time, we may also enter into an arrangement in which the right to use and control an identified underlying asset is embedded in another type of contract.

On January 1, 2019 we adopted Accounting Standards Update (ASU) 2016-02, Leases (Topic 842). See Note 16. We determine if an arrangement is a lease (including leases embedded in another type of contract) at inception. All of our leases are classified as operating leases under this new ASU. Operating leases are included in operating lease right-of-use assets, current operating lease liabilities and noncurrent operating lease liabilities in our Condensed Consolidated Balance Sheet beginning January 1, 2019. See Note 8.

Right-of-use assets represent our right to use an underlying asset for the lease term and operating lease liabilities represent our obligation to make lease payments arising from the lease. For leases in effect as of the January 1, 2019 date of adoption of the new ASU, the right-of-use operating lease assets and liabilities were recognized based on the estimated present value of remaining lease payments over the remaining lease term as of the adoption date. For new leases entered into subsequent to the date of adoption of the new ASU, the right-of-use operating lease assets and liabilities are recognized based on the estimated present value of lease payments over the lease term as of the respective lease commencement dates.

We use an estimated incremental borrowing rate to determine the present value of lease payments (unless we can determine the rate implicit in the lease, which is generally not the case). Our incremental borrowing rate for each of our leases is derived from available information, including our current debt and credit facilities and U.S. and European yield curves as well as publicly available data for instruments with similar characteristics, adjusted for factors such as collateralization and term. For leases in effect as of the January 1, 2019 date of adoption of the new ASU, we used an estimated incremental borrowing rate for each lease on the date of adoption. For new leases entered into subsequent to the date of adoption of the new ASU, we use an estimated incremental borrowing rate for each lease as of the respective lease commencement date.

Our leases generally do not include termination or purchase options. Certain of our leases include an option to renew the lease after expiration of the initial lease term, but we have not included such renewal periods in our lease term because it is not reasonably certain that we would exercise the renewal option. Our leases generally have fixed lease payments, with no contingent or incentive payments. Certain of our leases include variable lease payments that depend on a specified index or rate, and in accordance with ASU 2016-02 the determination of the operating lease liabilities is based on the index or rate existing at the date of adoption of the new ASU (for leases in effect as of January 1, 2019) or the index or rate in effect as of the lease commencement date (for leases entered into subsequent to the date of adoption of the new ASU). Our lease agreements do not contain any residual value guarantees.

With respect to our land lease associated with our Leverkusen facility, we periodically establish the amount of rent for such land lease by agreement with Bayer for periods of at least two years at a time. The lease agreement provides for no formula, index or other mechanism to determine changes in the rent of such land lease; rather, any change in the rent is subject solely to periodic negotiation between Bayer and us. As such, we will account for any change in the rent associated with such lease subsequent to the January 1, 2019 adoption of the new ASU as a lease modification.

During the first six months of 2019, our operating lease expense approximated $4.1 million (which amount approximates the amount of cash paid during the period for our operating leases included in the determination of our cash flows from operating activities). During the first six months of 2019, variable lease expense and short-term lease expense were not material. During the first six months of 2019, we entered into new operating leases which resulted in the recognition of nominal right-of-use operating lease assets and liabilities. At June 30, 2019, the weighted average remaining lease term of our operating leases was approximately 13 years, and the weighted average discount rate associated with such leases was approximately 4.5%. Such average remaining lease term is weighted based on each arrangement’s lease obligation, and such average discount rate is weighted based on each arrangement’s total remaining lease payments.

At June 30, 2019, maturities of our operating lease liabilities were as follows:

Years ending December 31,	Amount
	(In millions)
2019 (remainder of year)	$	3.9
2020		6.9
2021		6.1
2022		3.5
2023		2.3
2024 and thereafter		21.5
Total remaining lease payments		44.2
Less imputed interest		12.9
Total lease obligations		31.3
Less current obligations		6.7
Long term lease obligations	$	24.6

Approximately $7.2 million of the $31.3 million total lease obligations at June 30, 2019 relates to our Leverkusen facility lease discussed above.

At June 30, 2019, we have no significant lease commitments that have not yet commenced.

Net rent expense approximated $14 million in 2016, $16 million in 2017 and $15 million in 2018. At December 31, 2018, future minimum payments under non-cancellable operating leases having an initial or remaining term of more than one year were as follows:

Years ending December 31,	Amount
	(In millions)
2019	$	6.2
2020		5.0
2021		4.2
2022		3.2
2023		2.4
2024 and thereafter		21.5
Long term lease obligations	$	42.5

Approximately $17 million of the $42.5 million aggregate future minimum rental commitments at December 31, 2018 relates to our Leverkusen facility lease discussed above. The minimum commitment amounts for such lease included in the table above for each year through the 2050 expiration of the lease are based upon the current annual rental rate as of December 31, 2018.