Earnings Per Share (Schedule of Earnings Per Share Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent	$ 156	$ (22)	$ 344	$ 139	$ 132	$ 213	$ 158	$ (88)	$ 617	$ 415	$ 870
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Basic									67,800	65,400	62,700
Equivalent shares from outstanding stock options									500	400	1,200
Weighted Average Number of Shares Outstanding, Diluted									68,300	65,800	63,900
Earnings per share
Earnings Per Share, Basic (in dollars per share)	$ 2.32	$ (0.32)	$ 5.06	$ 2.04	$ 1.95	$ 3.13	$ 2.49	$ (1.41)	$ 9.10	$ 6.35	$ 13.88
Earnings Per Share, Diluted (in dollars per share)	$ 2.30	$ (0.32)	$ 5.02	$ 2.03	$ 1.94	$ 3.12	$ 2.48	$ (1.41)	$ 9.04	$ 6.31	$ 13.62