Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Impairment of oil and gas properties	$ 715,495	$ 1,440,418	$ 0
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool	129,900	100,600
Capitalized general and administrative costs	29,300	27,900	$ 25,200
Capitalized costs of oil and natural gas properties excluded from amortization	$ 1,580,305	$ 1,817,701		$ 575,521
Minimum
Property, Plant and Equipment [Line Items]
Expected number of years amortization will commence	3 years
Maximum
Property, Plant and Equipment [Line Items]
Expected number of years amortization will commence	5 years