Summary of Significant Accounting Policies - Summary of Property and Equipment Including Oil and Natural Gas Properties (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Oil and natural gas properties:
Unproved properties	$ 934,844	$ 1,044,469
Proved properties	1,179,866	802,112
Gross oil and natural gas properties	2,114,710	1,846,581
Less accumulated depreciation, depletion and amortization	(300,016)	(131,857)
Total oil and natural gas properties, net	1,814,694	1,714,724
Other property and equipment	11,391	8,912
Less accumulated depreciation	(3,010)	(809)
Other property and equipment, net	8,381	8,103
Total property and equipment, net	$ 1,823,075	$ 1,722,827