Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedule of Percent of Consolidated Revenue of Major Customers, Those Whose Total Represented 10% or More of Oil, Natural Gas and NGL Revenues

The percent of consolidated revenue of major customers, those whose total represented 10% or more of our oil, natural gas and NGL revenues, was as follows:

	Year Ended December 31,
	2017			2016			2015
Shell Trading (US) Company		80	%		68	%		68	%
Chevron U.S.A Inc.		*	*		14	%		16	%

** less than 10%

Summary of Supplementary Cash Flow Information

Supplementary cash flow information for each period presented was as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
Supplemental Non-Cash Transactions:
Capital expenditures included in accounts payable and accrued liabilities	$	40,626	$	13,832	$	30,125
Fair value of assets acquired	$	—	$	—	$	75,519
Fair value of liabilities assumed	$	—	$	—	$	75,519
Capital lease transaction	$	—	$	124,300	$	—
Supplemental Cash Flow Information:
Interest paid, net of amounts capitalized	$	47,994	$	55,254	$	37,247