8. Lease Obligations

From time to time, the Company enters into leasing arrangements for real estate, vehicles and construction equipment, including master leasing arrangements for vehicles and construction equipment. Some of the leases entered into under these agreements met the requirements for capitalization and were recorded as capital leases, while others were treated as operating leases. As of March 31, 2018, the Company had no outstanding commitments to enter into future leases under its master lease agreements.

Capital Leases

The Company leases some vehicles and certain equipment under capital leases. The economic substance of the leases is a financing transaction for acquisition of the vehicles and equipment. Accordingly, these leases are included in the balance sheets in property and equipment, net of accumulated depreciation, with a corresponding amount recorded in current portion of capital lease obligations or capital lease obligations, net of current maturities, as appropriate. The capital lease assets are amortized over the life of the lease or, if shorter, the life of the leased asset, on a straight-line basis and included in depreciation expense in the statements of operations. The interest associated with capital lease obligations is included in interest expense in the statements of operations.

As of March 31, 2018, the Company had approximately $3.4 million of capital lease obligations outstanding, $1.1 million of which was classified as a current liability. As of December 31, 2017, the Company had approximately $3.7 million of capital lease obligations outstanding, $1.1 million of which was classified as a current liability.

As of March 31, 2018 and December 31, 2017, $3.4 million and $3.7 million, respectively, of leased assets were capitalized in construction equipment, net of accumulated depreciation.

Operating Leases

The Company, from time to time, leases real estate, construction equipment and office equipment under operating leases with remaining terms ranging from one to six years.

Future Minimum Lease Payments

The future minimum lease payments required under capital leases and operating leases, together with the present value of capital leases, as of March 31, 2018 were as follows:

	Capital		Operating
(In thousands)	Lease Obligations		Lease Obligations

Remainder of 2018	$	889	$	3,124
2019		1,185		3,101
2020		1,185		2,225
2021		357		1,581
2022		—		1,009
Thereafter		—		487
Total minimum lease payments	$	3,616	$	11,527
Interest		(173)
Net present value of minimum lease payments		3,443
Less: Current portion of capital lease obligations		1,094
Long-term capital lease obligations	$	2,349