CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 6 months ended Jun. 30, 2017 - USD ($) shares in Thousands, $ in Thousands	Total		Total Stockholders' Equity	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Additional Paid-in Capital	Retained Earnings (Deficit)	Non-controlling Interest
Balance at beginning of period (in shares) at Dec. 31, 2016				6,497	10,225
Balance at beginning of period at Dec. 31, 2016	$ 123,736		$ 30,303	$ 65	$ 103	$ 0	$ 11	$ 25,413	$ 4,711	$ 93,433
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation	1,195		1,195					1,195
Restricted stock unit vesting (in shares)				121
Restricted stock unit vesting	1,054		1,054	$ 1				1,053
Consolidated net income	15,803	[1],[2]	3,349						3,349	12,454
Foreign currency translation adjustment for equity method investee	(75)	[1],[2]	(28)				(28)			(47)
Distributions paid to non-controlling unit holders	(19,822)									(19,822)
Net contribution by NG&E	210									210
Dividends paid to Class A common stockholders	(4,754)		(4,754)						(4,754)
Dividends to Preferred Stock	(1,174)		(1,174)						(1,174)
Conversion of Convertible Subordinated Notes to Class B Common Stock (in shares)					518
Conversion of Convertible Subordinated Notes to Class B Common Stock	7,795		7,795		$ 5			7,790		0
Treasury shares (in shares)						(60)
Stock Repurchased During Period, Value	1,285		1,285			$ 1,285
Stock split (in shares)				6,617	10,742
Stock Split				$ 66	$ 108			(174)
Balance at end of period (in shares) at Jun. 30, 2017				13,235	21,485
Balance at end of period at Jun. 30, 2017	$ 122,683		$ 36,455	$ 132	$ 216	$ (1,285)	$ (17)	$ 35,277	$ 2,132	$ 86,228
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock (in shares)						(60)

[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.