Oil and Gas Producing Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Cost incurred in oil and gas exploration and development activities

Total costs incurred in crude oil and natural gas exploration and development activities, all within the U.S., were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
Property acquisition costs:
Unproved	$	4	$	32
Exploration costs:
Expensed	5		291
Development costs	1,815		—
Total costs incurred	$	1,824	$	323

Proved developed and undeveloped oil and gas reserves

Proved developed and undeveloped reserves were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
	Natural	Crude	Natural	Crude
	Gas	Oil	Gas	Oil
	(Mcf)	(Bbls)	(Mcf)	(Bbls)
Total proved reserves:
Beginning of year	4,214	187	4,835	226
Revisions of previous estimates	—	—	65	24
Crude oil and natural gas reserves sold	(4,067)	(170)	(175)	(4)
Extensions, discoveries and other reserve additions	42	6	151	18
Production	(189)	(23)	(662)	(77)
End of year	—	—	4,214	187

Components of proved oil and gas reserves

The components of our previously owned proved crude oil and natural gas reserves, all within the U.S., were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
	Natural	Crude	Natural	Crude
	Gas	Oil	Gas	Oil
	(Mcf)	(Bbls)	(Mcf)	(Bbls)
Proved developed reserves	—	—	4,214	187
Proved undeveloped reserves	—	—	—	—
Total proved reserves	—	—	4,214	187

Standardized measure of discounted future net cash flows

The disclosures below do not purport to present the fair market value of our previously owned crude oil and natural gas reserves. An estimate of the fair market value would also take into account, among other things, the recovery of reserves in excess of proved reserves, anticipated future changes in prices and costs, a discount factor more representative of the time value of money and risks inherent in reserve estimates. The standardized measure of discounted future net cash flows was as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
Future gross revenues	$	—	$	17,938
Future costs:
Lease operating expenses	—		(12,421)
Development costs	—		(38)
Future net cash flows before income taxes	—		5,479
Discount at 10% per annum	—		(2,002)
Discounted future net cash flows before income taxes	—		3,477
Future income taxes, net of discount at 10% per annum	—		(1,217)
Standardized measure of discounted future net cash flows	$	—	$	2,260

Assumed market prices of oil and natural gas reserves and future net revenues

The estimated value of crude oil and natural gas reserves and future net revenues derived therefrom are highly dependent upon crude oil and natural gas commodity price assumptions. For these estimates, our independent petroleum engineers assumed market prices as follows for the periods indicated:

	Year Ended December 31,
	2017		2016
Market price:
Crude oil per barrel	$	—	$	38.34
Natural gas per thousand cubic feet (Mcf)	$	—	$	2.56

Effect of income taxes and discounting on the standardized measure of discounted future net cash flows

The effect of income taxes and discounting on the standardized measure of discounted future net cash flows was as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
Future net cash flows before income taxes	$	—	$	5,479
Future income taxes	—		(1,918)
Future net cash flows	—		3,561
Discount at 10% per annum	—		(1,301)
Standardized measure of discounted future net cash flows	$	—	$	2,260

Principal sources of changes in the standardized measure of discounted future net flows

The principal sources of changes in the standardized measure of discounted future net cash flows were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
Beginning of year	$	2,260	$	3,527
Sale of crude oil and natural gas reserves	(2,732)		(350)
Net change in prices and production costs	—		(1,391)
New field discoveries and extensions, net of future production costs	94		275
Sales of crude oil and natural gas produced, net of production costs	(476)		87
Net change due to revisions in quantity estimates	—		181
Accretion of discount	130		194
Production rate changes and other	(493)		(945)
Net change in income taxes	1,217		682
End of year	$	—	$	2,260

Results of operations for oil and gas producing activities

The results of crude oil and natural gas producing activities, excluding corporate overhead and interest costs, were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016
Revenues	$	1,427	$	3,410
Costs and expenses:
Production	(951)		(3,337)
Producing property impairment	—		(30)
Depreciation, depletion and amortization	(423)		(1,546)
Operating earnings (losses) before income taxes	53		(1,503)
Income tax benefit (expense)	(19)		526
Operating earnings (losses)	$	34	$	(977)