CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Sales and other operating revenues	$ 5,288,933	$ 5,312,686	$ 4,608,563
Gain (loss) on sale of assets	138,903	(87)	66
Interest and other income	48,248	77,490	10,973
Total revenues	5,476,084	5,390,089	4,619,602
Costs and Expenses
Lease operating expenses	1,089,888	1,252,812	1,079,136
Severance and ad valorem taxes	107,215	87,331	35,612
Exploration expenses, including undeveloped lease amortization	513,600	502,215	380,924
Selling and general expenses	364,004	379,167	249,532
Depreciation, depletion and amortization	1,906,247	1,553,394	1,253,095
Impairment of assets	51,314	21,587	200,000	[1]
Accretion of asset retirement obligations	50,778	48,996	38,361
Interest expense	136,424	124,423	54,105
Interest capitalized	(20,605)	(52,523)	(39,173)
Other expense	24,949
Total costs and expenses	4,223,814	3,917,402	3,251,592
Income from continuing operations before income taxes	1,252,270	1,472,687	1,368,010
Income tax expense	227,297	584,550	561,516
Income from continuing operations	1,024,973	888,137	806,494
Income (loss) from discontinued operations, net of income taxes	(119,362)	235,336	164,382
Net Income	$ 905,611	$ 1,123,473	$ 970,876
Income per Common Share - Basic
Income from continuing operations	$ 5.73	$ 4.73	$ 4.16
Income (loss) from discontinued operations	$ (0.67)	$ 1.25	$ 0.85
Net income - Basic	$ 5.06	$ 5.98	$ 5.01
Income per Common Share - Diluted
Income from continuing operations	$ 5.69	$ 4.69	$ 4.14
Income (loss) from discontinued operations	$ (0.66)	$ 1.25	$ 0.85
Net income - Diluted	$ 5.03	$ 5.94	$ 4.99
Average Common shares outstanding
Average Common shares outstanding - Basic	178,852,942	187,921,062	193,902,335
Average Common shares outstanding - Diluted	180,070,984	189,271,398	194,668,737

[1] Results exclude corporate overhead, interest and discontinued operations.