Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:
Crude oil and natural gas sales	$ 3,501,666	$ 2,315,840	$ 1,553,629
Crude oil and natural gas sales to affiliates	105,108	63,593	93,790
Gain (loss) on derivative instruments, net	(191,751)	154,016	(30,049)
Crude oil and natural gas service operations	40,127	39,071	32,419
Total revenues	3,455,150	2,572,520	1,649,789
Operating costs and expenses:
Production expenses	280,789	193,466	135,178
Production and other expenses to affiliates	6,111	6,675	4,632
Production taxes and other expenses	327,427	223,737	143,236
Exploration expenses	34,947	23,507	27,920
Crude oil and natural gas service operations	29,665	32,248	26,735
Depreciation, depletion, amortization and accretion	965,645	692,118	390,899
Property impairments	220,508	122,274	108,458
General and administrative expenses	144,379	121,735	72,817
Gain on sale of assets, net	(88)	(136,047)	(20,838)
Total operating costs and expenses	2,009,383	1,279,713	889,037
Income from operations	1,445,767	1,292,807	760,752
Other income (expense):
Interest expense	(235,275)	(140,708)	(76,722)
Other	2,557	3,097	3,415
Total other income (expense)	(232,718)	(137,611)	(73,307)
Income before income taxes	1,213,049	1,155,196	687,445
Provision for income taxes	448,830	415,811	258,373
Net income	$ 764,219	$ 739,385	$ 429,072
Basic net income per share (in dollars per share)	$ 4.15	$ 4.08	$ 2.42
Diluted net income per share (in dollars per share)	$ 4.13	$ 4.07	$ 2.41