Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator for Basic and Diluted Earnings Per Share - [Abstract]
Net Income (Loss)	$ (909,384)	$ 847,841	$ (899,571)	$ 1,483,267
Denominator for Basic Earnings Per Share - [Abstract]
Weighted Average Shares	578,719	577,460	578,581	577,333
Denominator for Diluted Earnings Per Share - [Abstract]
Adjusted Diluted Weighted Average Shares	578,719	580,247	578,581	580,204
Net Income (Loss) Per Share
Basic	$ (1.57)	$ 1.47	$ (1.55)	$ 2.57
Diluted	$ (1.57)	$ 1.46	$ (1.55)	$ 2.56
Stock Options, SARs and ESPP [Member]
Potential Dilutive Common Shares - [Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments	0	434	0	452
Net Income (Loss) Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	9,300	6,000	9,300	6,000
Restricted Stock/Units and Performance Units/Stock
Potential Dilutive Common Shares - [Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments	0	2,353	0	2,419
Net Income (Loss) Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,800		4,800