Operating Segment Information (Reconciliation of Segment Revenues to Total Revenues) (Details) - USD ($) $ in Thousands		1 Months Ended	2 Months Ended	3 Months Ended							4 Months Ended	8 Months Ended	12 Months Ended
		Sep. 30, 2016	Aug. 31, 2016	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Aug. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenues		$ 20,435		$ 31,753			$ 142,424	$ 257,895	$ 96,125	$ 243,589	$ 52,188
Predecessor
Segment Reporting Information [Line Items]
Total revenues			$ 64,686		$ (16,824)	$ 103,208						$ 151,070	$ 740,033	$ 701,654
Gas And Oil Production
Segment Reporting Information [Line Items]
Total revenues	[1]										43,044
Gas And Oil Production | Predecessor
Segment Reporting Information [Line Items]
Total revenues	[1]											115,178	624,222	472,870
Well Construction And Completion
Segment Reporting Information [Line Items]
Total revenues											2,326
Well Construction And Completion | Predecessor
Segment Reporting Information [Line Items]
Total revenues												19,157	76,505	173,564
Other Partnership Management
Segment Reporting Information [Line Items]
Total revenues	[2]										$ 6,818
Other Partnership Management | Predecessor
Segment Reporting Information [Line Items]
Total revenues	[2]											$ 16,735	$ 39,306	$ 55,220

[1] Includes gain (loss) on mark-to-market derivatives.

[2] Includes revenues and expenses from well services, gathering and processing, administration and oversight, and other, net that do not meet the quantitative threshold for reporting segment information.