Equity-Based Compensation - RSUs (Detail) - Restricted Stock Units [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity-Based Compensation
Unvested, Units, beginning of year	365,000
Granted, Units	120,000
Vested, Units	(97,000)
Forfeited, Units	(17,000)
Unvested, Units, end of year	371,000	365,000
Unvested, Weighted Average Per Share Fair Value, beginning of year	$ 131.26
Granted, Weighted Average Per Share Fair Value	151.70
Vested, Weighted Average Per Share Fair Value	123.85
Forfeited, Weighted Average Per Share Fair Value	141.17
Unvested, Weighted Average Per Share Fair Value, end of year	$ 139.37	$ 131.26
Total fair market value of vested awards	$ 15	$ 15	$ 12
Shares issued under the plan	69,000
Vested deferred units outstanding	27,000
Vesting period	3 years