Operating lease-related assets and liabilities (we do not have any material finance leases) reflected on our June 30, 2019 balance sheet and the weighted-average lease term and discount rate are as follows:



		June 30
in thousands	Classification on the Balance Sheet	2019
Assets
Operating lease right-of-use assets		$ 435,672
Accumulated amortization		(16,776)
Total lease assets	Operating lease right-of-use assets, net	$ 418,896
Liabilities
Current
Operating	Other current liabilities	$ 31,357
Noncurrent
Operating	Operating lease liabilities	396,952
Total lease liabilities		$ 428,309
Lease Term and Discount Rate
Weighted-average remaining lease term (years)
Operating leases		10.0
Weighted-average discount rate
Operating leases		4.4%

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 1 - 30 years, and lease terms (including options to extend) of 1 - 30 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 - 13 years, and lease terms of 2 - 80 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 - 97 years, and lease terms of 1 - 97 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 - 7 years, and lease terms of 2 - 76 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 2 - 3 years, and lease terms of 10 - 16 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 - 4 years, and lease terms of 0 - 4 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 material residual value guarantees or material termination options.

Lease expense for operating leases is recognized on a straight-line basis over the lease term. The components of nonmineral operating lease expense are as follows:



	Three Months Ended		Six Months Ended
	June 30		June 30
in thousands		2019		2019
Lease cost
Operating lease cost		$ 14,167		$ 28,294
Short-term lease cost ¹		7,922		16,623
Variable lease cost		3,489		6,557
Sublease income		(807)		(1,418)
Total lease cost		$ 24,771		$ 50,056

Total nonmineral operating lease expense for the prior year’s three and six months ended June 30, 2018 was $21,968,000 and $46,320,000, respectively.

Cash paid for operating leases was $25,513,000 for the six months ended June 30, 2019 and was reflected as a reduction to operating cash flows.

Maturity analysis on an undiscounted basis of our nonmineral lease liabilities as of June 30, 2019 is as follows:



		Operating
in thousands		Leases
Maturity of Lease Liabilities
2019 (remainder)		$ 26,537
2020		49,740
2021		45,807
2022		40,760
2023		36,203
Thereafter		606,079
Total minimum lease payments		$ 805,126
Less: Lease payments representing interest		376,817
Present value of future minimum lease payments		$ 428,309
Less: Current obligations under leases		31,357
Long-term lease obligations		$ 396,952

Future minimum operating lease payments under leases with initial or remaining noncancelable lease terms in excess of one year, exclusive of mineral leases, 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