Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator for Basic and Diluted Earnings Per Share - [Abstract]
Net Income (Loss)	$ 907,000	$ (910,000)	$ 1,584,000	$ (900,000)
Denominator for Basic Earnings Per Share - [Abstract]
Weighted Average Shares	580,000	579,000	580,000	579,000
Denominator for Diluted Earnings Per Share - [Abstract]
Adjusted Diluted Weighted Average Shares	584,000	579,000	583,000	579,000
Net Income (Loss) Per Share
Basic	$ 1.56	$ (1.57)	$ 2.73	$ (1.55)
Diluted	$ 1.55	$ (1.57)	$ 2.72	$ (1.55)
Stock Options, SARs and ESPP [Member]
Potential Dilutive Common Shares - [Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments	1,000	0	1,000	0
Net Income (Loss) Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,000	9,000	7,000	9,000
Restricted Stock/Units and Performance Units/Stock
Potential Dilutive Common Shares - [Abstract]
Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments	3,000	0	2,000	0
Net Income (Loss) Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		5,000		5,000