Long-Term Debt (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	May 19, 2016 USD ($)
Line of Credit Facility [Line Items]
Amortization of debt issuance costs	$ 100	$ 100	$ 259	$ 246
Unamortized debt issue costs	1,400		1,400		$ 1,700
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	215,600		215,600
Sub-limit which may be used for issuance of letters of credit	15,000		$ 15,000
Borrowing base amount						$ 200,000
Commitment fee on unutilized borrowing base			0.50%
Credit Agreement [Member] | Second full quarter after Catarina acquisition
Line of Credit Facility [Line Items]
Borrowing base multiplier			4.5
Credit Facility Maturing March 31, 2020
Line of Credit Facility [Line Items]
Maximum borrowing capacity	500,000		$ 500,000
lender loan
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000		$ 200,000
Minimum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Consolidated current asset ratio			1.0
Required interest coverage ratio			2.5
Exceeding of reserve-based credit facility over borrowing base (as a percent)			90.00%
Ownership percentage by subsidiary			50
Minimum [Member] | Credit Agreement [Member] | Scenario One
Line of Credit Facility [Line Items]
Debt to Adjusted EBITDA ratio	4.5		4.5
Minimum [Member] | Credit Agreement [Member] | Scenario Two
Line of Credit Facility [Line Items]
Debt to Adjusted EBITDA ratio	4.0		4.0
Minimum [Member] | Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Variable interest rate			2.25%
Minimum [Member] | Credit Agreement [Member] | ABR [Member]
Line of Credit Facility [Line Items]
Variable interest rate			1.25%
Maximum [Member] | Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Variable interest rate			3.25%
Maximum [Member] | Credit Agreement [Member] | ABR [Member]
Line of Credit Facility [Line Items]
Variable interest rate			2.25%