Earnings (Loss) Per Share (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Incremental common shares attributable to dilutive effect of share-based payment arrangements (in shares)	1,020,000
Antidilutive securities excluded from computation of earnings (in shares)	120,000	1,015,000
Treasury stock, shares, acquired (in shares)	66,000	435,376
Purchase of treasury stock	$ 3	$ 18