Note 10—Capital Leases

We lease vehicles and certain equipment under capital leases. The economic substance of the leases is as a financing transaction for acquisition of the vehicles and equipment, and accordingly, the leases are recorded as assets and liabilities. Included in depreciation expense is depreciation of vehicles and equipment held under capital leases, amortized over their useful lives on a straight-line basis.

At December 31, 2017, total assets under capital leases were $3.1 million, accumulated depreciation was $1.9 million, and the net book value was $1.2 million. For 2016, total assets under capital leases were $2.5 million, accumulated depreciation was $2.3 million, and the net book value of assets was $0.2 million.

The following is a schedule by year of the future minimum lease payments required under capital leases together with their present value as of December 31 (in thousands):


2018	$	134
2019		98
2020		90
2021		11
2022		—
Total minimum lease payments	$	333
Amounts representing interest		(5)
Net present value of minimum lease payments		328
Less: current portion of capital lease obligations		(132)
Long-term capital lease obligations	$	196