Revenue Recognition (Tables)

6 Months Ended

Jun. 30, 2018

Revenue From Contract With Customer [Abstract]

Schedule of Impact of Adoption

The impact of adoption in the current period results is as follows:

	Three Months Ended June 30, 2018								Six Months Ended June 30, 2018
	Under ASC 606			Under ASC 605			Increase/ (Decrease)		Under ASC 606			Under ASC 605			Increase/ (Decrease)
Upstream revenues	$	1,069		$	1,004		$	65	$	2,388		$	2,261		$	127
Marketing revenues		1,180			1,180			—		2,059			2,059			—
Total impacted revenues	$	2,249		$	2,184		$	65	$	4,447		$	4,320		$	127
Production expenses	$	572		$	507		$	65	$	1,115		$	988		$	127
Marketing expenses		1,160			1,160			—		2,033			2,033			—
Total impacted expenses	$	1,732		$	1,667		$	65	$	3,148		$	3,021		$	127
Loss from continuing operations    before income taxes	$	(481	)	$	(481	)	$	—	$	(726	)	$	(726	)	$	—

Schedule of Revenue from Contracts with Customers that are Disaggregated Based on Type of Good or Service

	Three Months Ended June 30, 2018						Six Months Ended June 30, 2018
	U.S.		Canada		Total		U.S.		Canada		Total
Revenues from contracts with    customers:
Oil	$	808	$	313	$	1,121	$	1,485	$	543	$	2,028
Gas		207		—		207		462		—		462
NGL		238		—		238		436		—		436
Oil, gas and NGL sales		1,253		313		1,566		2,383		543		2,926
Oil		766		24		790		1,297		41		1,338
Gas		160		—		160		315		—		315
NGL		230		—		230		406		—		406
Total marketing revenues		1,156		24		1,180		2,018		41		2,059
Total revenues from contracts with    customers	$	2,409	$	337	$	2,746	$	4,401	$	584	$	4,985