Long-Term Debt and Notes Payable - Additional Information (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 02, 2014	Dec. 31, 2014	Nov. 17, 2014	Apr. 16, 2015
Debt Instrument [Line Items]
Cross default provision, threshold amount	$ 10,000,000
Initial borrowing base				2,000,000,000
Interest expense	11,758,000	7,888,000
Capitalized interest expense	32,000	0
Loan limit percentage (less than)	10.00%
Credit facility cross default provision, threshold amount	75,000,000
Commitment fee (basis points)	0.30%
Syndicated Credit Facility | Credit Facility, September 2, 2014
Debt Instrument [Line Items]
Term of credit facility			5 years
Initial borrowing base			2,100,000,000
Maximum borrowing capacity			1,500,000,000		2,000,000,000
Debt covenant, debt to EBITDAX ratio	4.0
Debt covenant, current assets to current liabilities ratio	1.0
Debt covenant, minimum net present value of proved reserves to consolidated debt, ratio	1.50
Subsequent Event
Debt Instrument [Line Items]
Initial borrowing base						1,600,000,000
Subsequent Event | Syndicated Credit Facility | Credit Facility, September 2, 2014
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 1,600,000,000