v3.6.0.2
Net Income (Loss) Per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Numerator for Basic and Diluted Earnings per Share - [Abstract]                      
Net Income (Loss) $ (142,352) $ (190,000) $ (292,558) $ (471,776) $ (284,296) $ (4,075,739) $ 5,268 $ (169,748) $ (1,096,686) $ (4,524,515) $ 2,915,487
Denominator for Basic Earnings per Share - [Abstract]                      
Weighted Average Shares (in shares)                 553,384 545,697 543,443
Potential Dilutive Common Shares -[Abstract]                      
Stock Options/SARs (in shares)                 0 0 2,526
Restricted Stock/Units and Performance Units/Stock (in shares)                 0 0 2,570
Denominator for Diluted Earnings per Share - [Abstract]                      
Adjusted Diluted Weighted Average Shares (in shares) 567,337 547,838 547,335 546,715 546,432 545,920 549,683 544,998 553,384 545,697 548,539
Net Income (Loss) Per Share [Abstract]                      
Basic (in dollars per share) $ (0.25) [1] $ (0.35) [1] $ (0.53) [1] $ (0.86) [1] $ (0.52) [1] $ (7.47) [1] $ 0.01 [1] $ (0.31) [1] $ (1.98) $ (8.29) $ 5.36
Diluted (in dollars per share) $ (0.25) [1] $ (0.35) [1] $ (0.53) [1] $ (0.86) [1] $ (0.52) [1] $ (7.47) [1] $ 0.01 [1] $ (0.31) [1] $ (1.98) $ (8.29) $ 5.32
Antidilutive Stock Options and SARs excluded from Diluted Earnings Per Share Calculation (in shares)                 10,300 10,200 700
Restricted Stock and Restricted Stock Units and Performance Units and Performance Stock Excluded from Calculation                 4,500 5,300  
[1] The sum of quarterly net income (loss) per share may not agree with total year net income (loss) per share as each quarterly computation is based on the weighted average of common shares outstanding.