Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income attributable to common shareholders	$ 203	$ 247
Denominator:
Weighted-average common shares outstanding for basic earnings per share (in shares)	164,864,077	165,343,968
Weighted-average effect of dilutive securities:
Employee equity awards (in shares)	1,912,439	1,682,787
Weighted-average common shares outstanding for diluted earnings per share (in shares)	166,776,516	167,026,755
Basic and diluted earnings per share:
Basic earnings per share (in dollars per share)	$ 1.23	$ 1.49
Diluted earnings per share (in dollars per share)	$ 1.22	$ 1.48

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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