Operating Segment Information (Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Goodwill	$ 31,784	$ 31,784
Total assets	2,881,286	2,343,800
Operating Segments | Gas And Oil Production
Segment Reporting Information [Line Items]
Goodwill	18,145	18,145
Total assets	2,725,982	2,170,712
Operating Segments | Well Construction And Completion
Segment Reporting Information [Line Items]
Goodwill	6,389	6,389
Total assets	23,561	55,031
Operating Segments | Other Partnership Management
Segment Reporting Information [Line Items]
Goodwill	7,250	7,250
Total assets	56,123	56,493
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Total assets	$ 75,620	$ 61,564