Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income attributable to common shareholders	$ 264	$ 150	$ 708	$ 571
Denominator:
Weighted-average common shares outstanding for basic earnings per share (in shares)	164,171,067	164,331,832	164,377,053	165,086,951
Weighted-average effect of dilutive securities:
Employee equity awards (in shares)	2,328,540	1,705,665	2,071,848	1,611,232
Contingent issuance of stock (in shares)	992,247	992,247	330,749	330,749
Weighted-average common shares outstanding for diluted earnings per share (in shares)	167,491,854	167,029,744	166,779,650	167,028,932
Basic and diluted earnings per share:
Basic earnings per share (in dollars per share)	$ 1.61	$ 0.91	$ 4.31	$ 3.46
Diluted earnings per share (in dollars per share)	$ 1.58	$ 0.90	$ 4.25	$ 3.42
Securities excluded from the computation of diluted earnings per share (in shares)	0