Net Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net earnings attributable to common stockholders	$ 317	$ 493	$ 290
Basic earnings per common share:
Weighted-average common shares outstanding (in shares)	214.9	220.2	232.6
Net earnings attributable to common stockholders (in dollars per share)	$ 1.48	$ 2.24	$ 1.25
Diluted earnings per common share:
Weighted-average common shares outstanding (in shares)	214.9	220.2	232.6
Dilutive common shares—stock options (in shares)	0.3	1.4	1.2
Diluted weighted-average shares outstanding (in shares)	215.2	221.6	233.8
Net earnings attributable to common stockholders (in dollars per share)	$ 1.47	$ 2.23	$ 1.24
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3.3	1.4	1.5