Lawsuits, Claims, Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of future minimum lease payments for non-cancelable operating leases

At December 31, 2017, future net minimum lease payments for non-cancelable operating leases (excluding oil and natural gas and other mineral leases, utilities, taxes and insurance and maintenance expense) totaled:

	Amount
	(in thousands)
2018	$	1,349
2019	1,141
2020	85
2021	87
2022	88
Thereafter	—
Total minimum lease payments	$	2,750

At September 30, 2018, future net minimum lease payments for non-cancelable operating leases (excluding oil and natural gas and other mineral leases, utilities, taxes and insurance and maintenance expense) totaled:

	Amount
	(in thousands)
2018	$	362
2019	1,290
2020	316
2021	321
2022	326
Thereafter	229
Total minimum lease payments	$	2,844