We have leases for office and shop space, as well as for equipment primarily utilized in our construction projects. As of June 30, 2019, our lease contracts were classified as operating leases and had terms ranging from month-to-month to 29 years. As of June 30, 2019, our operating leases were included in ROU assets, accrued and other current liabilities and lease liabilities on our condensed consolidated balance sheets and were $73.4 million, $15.6 million and $60.9 million, respectively. As of June 30, 2019, we had no lease contracts that had not yet commenced but created significant rights and obligations and no agreements had embedded leases.

Lease expense was $4.6 million and $8.9 million during the three and six months ended June 30, 2019, which included operating lease costs related to short-term leases and variable lease costs.

As of June 30, 2019, our weighted-average remaining lease term was 6.3 years and the weighted-average discount rate was 4.08%.

As of June 30, 2019, the lease liability is equal to the present value of the remaining lease payments, discounted using the incremental borrowing rate on our secured debt using a single maturity discount rate as it is not materially different than the discount rates applied to each of the leases in the portfolio.

The following table summarizes our undiscounted lease liabilities outstanding as of June 30, 2019:

Remainder of 2019	$	9,543
2020		18,541
2021		17,303
2022		15,222
2023		10,268
2024 through 2035		20,790
Total future minimum lease payments	$	91,667
Less: imputed interest		15,219
Total	$	76,448