Share-Based Compensation - STAP Awards (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Awards granted
Aggregate STAP liability	$ 40.6		$ 80.8
STAP awards
Awards granted
Grant expiration period from the grant date	10 years
Award vesting period	4 years
Weighted-average assumptions used to measure the fair value of the outstanding STAP awards:
Expected term of awards (in years)	7 months 6 days	1 year
Expected volatility	26.70%	31.20%
Risk-free interest rate (as a percent)	5.50%	4.10%
Expected dividend yield	0.00%	0.00%
Closing price of common stock (in dollars per share)	$ 225.87	$ 209.38	$ 278.09
Number of Awards
Outstanding at beginning of period (in shares)	555,600
Granted (in shares)	0
Exercised (in shares)	(77,450)
Forfeited (in shares)	(850)
Outstanding at end of period (in shares)	477,300
Exercisable at end of period (in shares)	477,300
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)	$ 140.54
Granted (in dollars per share)	0
Exercised (in dollars per share)	100.58
Forfeited (in dollars per share)	60.16
Outstanding at end of period (in dollars per share)	147.17
Exercisable at end of period (in dollars per share)	$ 147.17
Weighted Average Remaining Contractual Term (in Years)
Outstanding at end of the period	1 year 3 months 18 days
Exercisable at end of period	1 year 3 months 18 days
Aggregate Intrinsic Value (in millions)
Outstanding at end of period	$ 37.6
Exercisable at end of period	$ 37.6