Revenue Recognition - Impact on Statement of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating revenues
Revenues	$ 57,489	$ 41,233
Operating costs and expenses
Lease operating	10,229	8,806
Production and ad valorem taxes	2,751	(906)
Transportation and processing costs	706
Exploration	3,299	2,944
Depletion, depreciation and amortization	41,441	35,654
Accretion of ARO liability	251	201
General and administrative	7,570	8,041
Total operating expenses	66,247	54,740
Operating income (loss)	(8,758)	(13,507)
Other income (expense)
Interest expense	(21,862)	(12,887)
Net gain (loss) on commodity derivatives	(9,022)	22,320
Other income (expense)	7,730	580
Other income (expense), net	(23,154)	10,013
Income (loss) before income tax	(31,912)	(3,494)
Income tax provision (benefit)	(2,992)	21
Net income (loss)	(28,920)	(3,515)
Net income (loss) attributable to non-controlling interests	(3,559)	(2,128)
Net income (loss) attributable to controlling interests	(25,361)	(1,387)
Dividends and accretion on preferred stock	(1,968)	(2,027)
Net income (loss) attributable to common shareholders	$ (27,329)	$ (3,414)
Earnings (loss) per share:
Basic - Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.30)	$ (0.05)
Diluted - Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.30)	$ (0.05)
Weighted average Class A shares outstanding:
Basic (in shares)	91,064	62,197
Diluted (in shares)	91,064	62,197
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Operating revenues
Revenues	$ (706)
Operating costs and expenses
Transportation and processing costs	(706)
Total operating expenses	(706)
Other income (expense)
Net income (loss)	0
Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
Operating revenues
Revenues	56,783
Operating costs and expenses
Lease operating	10,229
Production and ad valorem taxes	2,751
Exploration	3,299
Depletion, depreciation and amortization	41,441
Accretion of ARO liability	251
General and administrative	7,570
Total operating expenses	65,541
Operating income (loss)	(8,758)
Other income (expense)
Interest expense	(21,862)
Net gain (loss) on commodity derivatives	(9,022)
Other income (expense)	7,730
Other income (expense), net	(23,154)
Income (loss) before income tax	(31,912)
Income tax provision (benefit)	(2,992)
Net income (loss)	(28,920)
Net income (loss) attributable to non-controlling interests	(3,559)
Net income (loss) attributable to controlling interests	(25,361)
Dividends and accretion on preferred stock	(1,968)
Net income (loss) attributable to common shareholders	$ (27,329)
Earnings (loss) per share:
Basic - Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.30)
Diluted - Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.30)
Weighted average Class A shares outstanding:
Basic (in shares)	91,064
Diluted (in shares)	91,064
Oil and Gas
Operating revenues
Revenues	$ 58,138	$ 40,677
Oil and Gas | Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Operating revenues
Revenues	(706)
Oil and Gas | Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
Operating revenues
Revenues	57,432
Other revenues
Operating revenues
Revenues	(649)	$ 556
Other revenues | Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
Operating revenues
Revenues	$ (649)