Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net income available to common stockholders	$ 679	$ 703	$ 591	$ 451	$ 639	$ 606	$ 493	$ 367	$ 2,424	$ 2,105	$ 1,386
Denominator:
Denominator for basic earnings per share—weighted-average common shares (in shares)									68,470	70,703	72,432
Effect of dilutive securities:
Denominator for diluted earnings per share—adjusted weighted-average common shares (in shares)									68,710	70,973	72,817
Basic earnings per share (in dollars per share)	$ 10.04	$ 10.30	$ 8.60	$ 6.50	$ 9.20	$ 8.69	$ 6.91	$ 5.07	$ 35.40	$ 29.77	$ 19.14
Diluted earnings per share (in dollars per share)	$ 10.01	$ 10.29	$ 8.58	$ 6.47	$ 9.15	$ 8.66	$ 6.90	$ 5.05	$ 35.28	$ 29.65	$ 19.04
Employee stock options
Effect of dilutive securities:
Share-based payment arrangements (in shares)									4	4	4
Restricted stock units
Effect of dilutive securities:
Share-based payment arrangements (in shares)									236	266	381