Operating lease-related assets and liabilities (we do not have any material finance leases) reflected on our December 31, 2019 balance sheet and the weighted-average lease term and discount rate are as follows:



in thousands	Classification on the Balance Sheet	2019
Assets
Operating lease right-of-use assets		$ 441,656
Accumulated amortization		(33,467)
Total lease assets	Operating lease right-of-use assets, net	$ 408,189
Liabilities
Current
Operating	Other current liabilities	$ 29,971
Noncurrent
Operating	Operating lease liabilities	388,042
Total lease liabilities		$ 418,013
Lease Term and Discount Rate
Weighted-average remaining lease term (years)
Operating leases		9.9
Weighted-average discount rate
Operating leases		4.3%

Our portfolio of nonmineral leases is composed almost entirely of operating leases for real estate (including office buildings, aggregates sales yards, and concrete and asphalt sites) and equipment (including railcars and rail track, barges, office equipment and plant equipment).

Our building leases have remaining noncancelable periods of 0 - 8 years and lease terms (including options to extend) of 0 - 27 years. Key factors in determining the certainty of lease renewals include the location of the building, the value of leasehold improvements and the cost to relocate. Rental payments for certain of our building leases are periodically adjusted for inflation, and this variable component is recognized as expense when incurred. Many of our building leases contain common area maintenance charges which we include in the calculation of our lease liability (the lease consideration is not allocated between the lease and non-lease components).

Our aggregates sales yard leases have remaining noncancelable periods of 0 - 29 years and lease terms of 0 - 79 years. The key factor in determining the certainty of lease renewals is the financial impact of extending the lease, including the reserve life of the sourcing aggregates quarry. Certain aggregates sales yard lease agreements include rental payments based on a percentage of sales over contractual levels or the number of shipments received into the sales yard. Variable payments for these sales yards comprise a majority of the overall variable lease cost presented in the table below.

Our concrete and asphalt site leases have remaining noncancelable periods of 0 - 20 years and lease terms of 0 - 79 years. The key factor in determining the certainty of lease renewals is the financial impact of extending the lease, including the reserve life of the sourcing aggregates quarry. Rental payments are generally fixed for our concrete and asphalt sites.

Our rail (car and track) leases have remaining noncancelable periods of 0 - 4 years and lease terms of 1 - 65 years. Key factors in determining the certainty of lease renewals include the market rental rate for comparable assets and, in some cases, the cost incurred to restore the asset. Rental payments are fixed for our rail leases. The majority of our rail leases contain substitution rights that allow the supplier to replace damaged equipment. Because these rights are generally limited to either replacing railcars or moving our placement on rail track for purposes of repair or maintenance, we do not consider these substitution rights to be substantive and have recorded a lease liability and ROU asset for all leased rail.

Our barge leases have remaining noncancelable periods of 1 - 2 years and lease terms of 9 - 15 years. Key factors in determining the certainty of lease renewals include the market rental rate for comparable assets and, in some cases, the cost incurred to restore the asset. Rental payments are fixed. Like our rail leases, our barge leases contain non-substantive substitution rights that are limited to replacing barges in need of repair or maintenance.

Office and plant equipment leases have remaining noncancelable periods of 0 - 5 years and lease terms of 0 - 5 years. The key factor in determining the certainty of lease renewals is the market rental rate for comparable assets. Rental payments are generally fixed for our equipment leases with terms greater than 1 year. The significant majority of our short-term lease cost presented in the table below is derived from office and plant equipment leases with terms of 1 year or less.

Our lease agreements do not contain residual value guarantees, restrictive covenants or early termination options that we deem material.

Lease expense for operating leases is recognized on a straight-line basis over the lease term. The components of operating lease expense for the year ended December 31, 2019 are as follows:



in thousands								2019
Lease Cost
Operating lease cost								$ 56,546
Short-term lease cost ¹								35,487
Variable lease cost								13,739
Sublease income								(3,108)
Total lease cost								$ 102,664

Total operating lease expense for the years ended December 31, 2018 and 2017 was $131,015,000 and $110,358,000, respectively.

Cash paid for operating leases was $52,660,000 for 2019 and was reflected as a reduction to operating cash flows.

Maturity analysis on an undiscounted basis of our operating lease liabilities (see Note 12 for mineral lease payments) as of December 31, 2019 is as follows:



		Operating
in thousands		Leases
Maturity of Lease Liabilities
2020		$ 49,767
2021		46,100
2022		41,957
2023		37,276
2024		34,073
Thereafter		576,200
Total minimum lease payments		$ 785,373
Less: Lease payments representing interest		367,360
Present value of future minimum lease payments		$ 418,013
Less: Current obligations under leases		29,971
Long-term lease obligations		$ 388,042

Future minimum operating lease payments under leases with initial or remaining noncancelable lease terms in excess of one year, exclusive of mineral leases, reported as of December 31, 2018 were payable as follows:



in thousands
Future Minimum Operating Lease Payments
2019	$ 47,979
2020	43,540
2021	35,732
2022	27,463
2023	19,707
Thereafter	195,104
Total	$ 369,525