Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator for Basic and Diluted Earnings Per Share - [Abstract]
Net Income (Loss)	$ (4,075,739)	$ 1,103,618	$ (4,240,219)	$ 2,470,899
Denominator for Basic Earnings Per Share - [Abstract]
Weighted Average Shares	545,920	543,984	545,466	543,086
Potential Dilutive Common Shares -[Abstract]
Stock Options/SARs	0	2,760	0	2,644
Restricted Stock/Units and Performance Units/Stock	0	2,774	0	2,671
Denominator for Diluted Earnings Per Share - [Abstract]
Adjusted Diluted Weighted Average Shares	545,920	549,518	545,466	548,401
Net Income (Loss) Per Share [Abstract]
Basic	$ (7.47)	$ 2.03	$ (7.77)	$ 4.55
Diluted	$ (7.47)	$ 2.01	$ (7.77)	$ 4.51
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Anti-dilutive Stock Options and SARs excluded from Diluted Earnings Per Share Calculation	9,800	200	10,000	200
Restricted Stock and Restricted Stock Units and Performance Units and Performance Stock Excluded from Calculation	5,400		5,400