Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Numerator:
Net income	$ 301	$ 301	$ 309	$ 321	$ 602	$ 630
Denominator:
Shares outstanding at the beginning of the period (in shares)		58,100		57,700			57,800	57,400
Weighted-average number of shares issued:
Stock-based compensation (in shares)	0		0		200	200
Denominator for basic net income per share (in shares)	58,100		57,700		58,000	57,600
Effect of dilutive securities:
Stock-based compensation (in shares)	100		200		300	400
Denominator for diluted net income per share (in shares)	58,200		57,900		58,300	58,000
Net income per share:
Net income per share - Basic (in dollars per share)	$ 5.18		$ 5.37		$ 10.38	$ 10.95
Net income per share - Diluted (in dollars per share)	$ 5.17		$ 5.35		$ 10.33	$ 10.87
Potentially dilutive common shares (in shares)	208				140