Transactions with Affiliates (Details) - USD ($)						3 Months Ended		6 Months Ended
		Dec. 27, 2016	Aug. 23, 2016	Aug. 01, 2016	Jan. 01, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017		Jun. 30, 2016		Dec. 31, 2016	Jul. 31, 2015	Jul. 08, 2015
Related Party Transaction [Line Items]
Accounts receivable—affiliates						$ 3,883,000		$ 3,883,000				$ 2,624,000
Accounts payable—affiliates						4,089,000		4,089,000				3,775,000
Net asset optimization revenues	[1],[2],[3]					(168,000)	$ (677,000)	(361,000)		$ (150,000)
Retail cost of revenues (less than)	[1],[2],[4]					114,637,000	56,963,000	260,398,000		125,763,000
General and administrative expense - affiliates	[1],[2],[5]					19,346,000	19,799,000	43,839,000		37,179,000
Proceeds from disgorgement of stockholders short-swing profits								666,000	[6]	580,000	[7]
Subordinated debt—affiliate						15,000,000		$ 15,000,000				$ 5,000,000
Tax receivable agreement, net cash savings (as a percent)								15.00%
Common Class B
Related Party Transaction [Line Items]
Share price (in dollars per share)			$ 10	$ 10
Convertible Debt | CenStar | Censtar Convertible Debt
Related Party Transaction [Line Items]
Notes, issued amount														$ 2,100,000.0
Convertible Debt | Oasis | Oasis Power Holdings Convertible Debt
Related Party Transaction [Line Items]
Notes, issued amount													$ 5,000,000.0
Subordinated Debt | Retailco
Related Party Transaction [Line Items]
Subordinated borrowing, interest rate		5.00%
Subordinated debt—affiliate		$ 25,000,000
Subordinated debt, advances		$ 1,000,000
Subordinated debt, interest rate on advances		5.00%
Minimum availability under the borrowing base		$ 5,000,000
Retailco
Related Party Transaction [Line Items]
Proceeds from disgorgement of stockholders short-swing profits						0		$ 700,000
NuDevco Retail Holdings and NuDevco Retail | Tax Receivable Agreement
Related Party Transaction [Line Items]
Initial TRA payment						1,400,000		1,400,000
Affiliated Entity
Related Party Transaction [Line Items]
General and administrative expense - affiliates							4,600,000			9,600,000
Affiliated Entity | Purchased Natural Gas From Affiliate
Related Party Transaction [Line Items]
Cost of revenues						0	400,000	0		1,600,000.0
Affiliated Entity | Purchased Natural Gas Sold To Affiliate
Related Party Transaction [Line Items]
Net asset optimization revenues						0	100,000	0		200,000
Affiliated Entity | Marlin Transportation Agreement
Related Party Transaction [Line Items]
Retail cost of revenues (less than)								0		100,000
Affiliated Entity | Allocated Overhead Costs
Related Party Transaction [Line Items]
General and administrative expense - affiliates						6,300,000	3,800,000	13,700,000		8,000,000
Affiliated Entity | Property and Equipment Capitalized
Related Party Transaction [Line Items]
Amount capitalized for application, development and implementation of various systems							$ 500,000			1,100,000
Affiliated Entity | Retailco
Related Party Transaction [Line Items]
Service contract term					1 year
Service contract, renewal term					1 year
Affiliated Entity | Retailco | Allocated Overhead Costs
Related Party Transaction [Line Items]
General and administrative expense - affiliates						5,400,000		11,900,000
Affiliated Entity | Retailco | Property and Equipment Capitalized
Related Party Transaction [Line Items]
Amount capitalized for application, development and implementation of various systems						$ 200,000		300,000
NuDevco Retail and Retailco
Related Party Transaction [Line Items]
Payments of distributions to affiliates								$ 7,800,000		6,400,000
Tax receivable agreement, net cash savings (as a percent)								85.00%
NuDevco Retail and Retailco | Payment of Income Taxes Incurred by the Company
Related Party Transaction [Line Items]
Payments of distributions to affiliates								$ 12,000,000		$ 3,500,000
Subsidiary of Common Parent | Retailco | Common Class B
Related Party Transaction [Line Items]
Number of shares issued for acquisition (shares)				1,399,484
Value of shares issued for acquisition				$ 14,000,000
Subsidiary of Common Parent | National Gas & Electric, LLC | Common Class B
Related Party Transaction [Line Items]
Number of shares issued for acquisition (shares)			4,000,000
NuDevco Retail Holdings and NuDevco Retail
Related Party Transaction [Line Items]
Tax receivable agreement, deferral period								5 years
Tax receivable agreement, coverage percentage								130.00%
Tax receivable agreement, target dividend (in dollars per share)								$ 0.18125

[1] Financial information has been recast to include results attributable to the acquisition of Perigee Energy, LLC by an affiliate on February 3, 2017. See Notes 2 and 3 "Basis of Presentation and Summary of Significant Accounting Policies" and "Acquisitions" for further discussion.

[2] Financial information has been recast to include results attributable to the acquisition of the Major Energy Companies by an affiliate on April 15, 2016. See Note 2 and 3 "Basis of Presentation and Summary of Significant Accounting Policies" and "Acquisitions" for further discussion.

[3] Net asset optimization revenues (expenses) includes asset optimization revenues—affiliates of $0 and $41 for the three months ended June 30, 2017 and 2016, respectively, and asset optimization revenues—affiliates cost of revenues of $0 and $376 for the three months ended June 30, 2017 and 2016, respectively, and asset optimization revenues—affiliates of $0 and $154 for the six months ended June 30, 2017 and 2016, respectively, and asset optimization revenue—affiliates cost of revenues of $0 and $1,633 for the six months ended June 30, 2017 and 2016, respectively.

[4] Retail cost of revenues includes retail cost of revenues—affiliates of $0 and less than $100 for the three months ended June 30, 2017 and 2016, respectively, and $0 and less than $100 for the six months ended June 30, 2017 and 2016, respectively.

[5] General and administrative includes general and administrative expense—affiliates of $6,100 and $4,000 for the three months ended June 30, 2017 and 2016, respectively, and $13,400 and $8,400 for the six months ended June 30, 2017 and 2016, respectively.

[6] Financial information has been recast to include results attributable to the acquisition of Perigee Energy, LLC by an affiliate on February 3, 2017. See Notes 2 and 3 "Basis of Presentation and Summary of Significant Accounting Policies" and "Acquisitions," respectively, for further discussion.

[7] Financial information has been recast to include results attributable to the acquisition of the Major Energy Companies by an affiliate on April 15, 2016. See Notes 2 and 3 "Basis of Presentation and Summary of Significant Accounting Policies" and "Acquisitions," respectively, for further discussion.