Schedule of Computation of Basic and Diluted EPS under Two-class Method (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income attributable to common shareholders	[1]	$ 435	$ 187	$ 462
Denominator:
Basic weighted average common stock	[1]	87.5	87.3	87.2
Added: Weighted average stock options/share awards	[1]	0.2	0.2	0.2
Diluted weighted average common stock		87.7	87.5	87.4
Basic earnings per share		$ 4.97	$ 2.14	$ 5.29
Diluted earnings per share		$ 4.96	$ 2.14	$ 5.29

[1] The Company’s unvested RSUs and PSs, of which some included the right to receive non-forfeitable dividend equivalents, are considered participating securities. Calculations of EPS under the two-class method exclude from the numerator any dividends paid or owed on participating securities and any undistributed earnings considered to be attributable to participating securities. The related participating securities are similarly excluded from the denominator. However, these participating securities have been immaterial for all the years presented.