Acquisitions and Divestitures - Additional Information (Details) $ / shares in Units, $ in Thousands				7 Months Ended	12 Months Ended
	Aug. 02, 2017 USD ($)	Jun. 15, 2017 USD ($) $ / shares shares	Aug. 02, 2016 USD ($) a Well shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
Business Acquisition [Line Items]
Acquisition of oil and gas properties					$ 113,726	$ 4,340
Preferred Stock, par value | $ / shares				$ 0.001	$ 0.001
Acquisition costs					$ 3,202
Preferred stock issued to finance acquisition
Revenues					94,068	57,972
Direct operating expenses					$ 129,509	$ 122,479
Series B Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Preferred Stock, par value | $ / shares				$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares issued | shares				0	0	0
Series A-1 Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Preferred Stock, par value | $ / shares				$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares issued | shares				83,968	83,968	0
Battlecat Oil & Gas, LLC
Business Acquisition [Line Items]
Purchase consideration of oil and gas properties		$ 59,800
Acquisition of oil and gas properties		55,000
Purchase consideration paid to acquire proved reserves		56,300
Purchase consideration paid to acquire unproved reserves		2,900
Purchase consideration paid to acquire unevaluated acreage and other assets		600
Asset retirement obligations recorded with the acquisition of properties		200
Fair value of net assets acquired		59,600
Acquisition costs		$ 1,500
Effective date of acquisition		Apr. 01, 2017
Revenues				$ 2,200
Direct operating expenses				600
Battlecat Oil & Gas, LLC | Series B Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares		1,184,632
Preferred Stock, par value | $ / shares		$ 0.001
Value of shares issued in connection with acquisition		$ 4,800
SN Marquis LLC
Business Acquisition [Line Items]
Purchase consideration of oil and gas properties		50,000
Acquisition of oil and gas properties		44,000
Purchase consideration paid to acquire proved reserves		48,000
Purchase consideration paid to acquire unproved reserves		600
Asset retirement obligations recorded with the acquisition of properties		1,900
Fair value of net assets acquired		48,100
Acquisition costs		$ 1,200
Effective date of acquisition		Jan. 01, 2017
Purchase consideration paid to acquire land, building and other assets		$ 1,400
Revenues				13,200
Direct operating expenses				$ 3,810
SN Marquis LLC | SN UR Holdings, LLC
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares		1,500,000
SN Marquis LLC | Series B Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares		1,500,000
Value of shares issued in connection with acquisition		$ 6,000
Battlecat and Marquis
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares		1,500,000
Preferred stock issued to finance acquisition		$ 80,000
Preferred stock issued to finance acquisition, initial conversion price | $ / shares		$ 6.00
Senior Secured Credit Facility issue to finance acquisition		$ 24,000
Battlecat and Marquis | Series B Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares		1,184,632
Battlecat and Marquis | Series A-1 Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares issued | shares		5,400
Battlecat and Marquis | Series A-2 Convertible Participating Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares issued | shares		74,600
Fort Worth, Texas
Business Acquisition [Line Items]
Acquisition price of an office building	$ 10,000
Brazos County | Juneau Energy, LLC
Business Acquisition [Line Items]
Acquisition of oil and gas properties			$ 5,500
Purchase and sale agreement date			Aug. 02, 2016
Undivided interest acquired in producing wells			50.00%
Productive Oil Wells, Number of Wells | Well			2
Net mineral acres | a			1,300
Brazos County | Class A Voting Common Stock | Juneau Energy, LLC
Business Acquisition [Line Items]
Number of shares issued in connection with acquisition | shares			500,227