Stock-Based Compensation - Stock Award Information and Fair Value Assumptions (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Unrecognized compensation cost related to stock options	$ 34.7
Stock-based compensation expense
Total stock-based compensation cost	32.8	$ 31.5	$ 25.7
Capitalized cost during the period	(3.3)	(4.5)	(1.9)
Amortization of capitalized cost during the period	3.4	4.7	1.2
Total stock-based compensation expense	32.9	31.7	25.0
Income tax benefit	18.7	$ 11.4	$ 11.5
Unrecognized compensation cost related to awards other than options	$ 34.7
Weighted average period of recognition of unrecognized compensation cost related to restricted stock awards	1 year 2 months 12 days
Executive Incentive Program
Stock-based compensation
Shares available for grant under the plan (in shares)	2,800
Restricted shares, performance shares, or other full value awards | Executive Incentive Program
Stock-based compensation
Shares available for grant under the plan (in shares)	800
Stock options - annual equity grant
Stock-based compensation
Stock options granted (in shares)	117
Weighted-average assumptions used to estimate grant date fair value of stock options
Expected dividend yield (as a percent)	1.20%	1.20%	0.90%
Expected life in years	4 years 8 months 12 days	4 years 7 months 6 days	4 years 8 months 12 days
Expected volatility (as a percent)	32.10%	32.40%	29.10%
Risk-free interest rate (as a percent)	3.90%	3.60%	1.80%
Weighted average grant date fair value (in dollars per share)	$ 97.11	$ 74.20	$ 55.96
Fair value of equity awards granted	$ 11.4	$ 13.3	$ 12.8
Restricted stock awards
Stock-based compensation
Awards granted (in shares)	36
Unrecognized compensation cost related to stock options	$ 9.1
Stock-based compensation expense
Total stock-based compensation cost	$ 9.4	8.3	7.2
Vesting period	3 years
Unrecognized compensation cost related to awards other than options	$ 9.1
Weighted average period of recognition of unrecognized compensation cost related to restricted stock awards	1 year 8 months 12 days
Performance share awards
Stock-based compensation
Awards granted (in shares)	24
Unrecognized compensation cost related to stock options	$ 10.7
Stock-based compensation expense
Total stock-based compensation cost	$ 9.4	8.8	8.3
Vesting period	3 years
Unrecognized compensation cost related to awards other than options	$ 10.7
Weighted average period of recognition of unrecognized compensation cost related to restricted stock awards	1 year 8 months 12 days
Q2 2022 Stock Option and Stock Appreciation Right Grant
Stock-based compensation expense
Total stock-based compensation cost	$ 5.0	6.7	2.9
Capitalized cost during the period	$ (0.4)	(0.5)	(0.7)
Stock option awards
Stock-based compensation
Stock options granted (in shares)	117
Unrecognized compensation cost related to stock options	$ 11.1
Stock-based compensation expense
Total stock-based compensation cost	$ 14.0	$ 14.4	$ 10.2
Vesting period	3 years
Maximum term life	10 years
Unrecognized compensation cost related to awards other than options	$ 11.1
2022 Broad-based Grant
Weighted-average assumptions used to estimate grant date fair value of stock options
Expected dividend yield (as a percent)			1.00%
Expected life in years			3 years 9 months 18 days
Expected volatility (as a percent)			31.90%
Risk-free interest rate (as a percent)			3.90%
Weighted average grant date fair value (in dollars per share)			$ 80.23
Fair value of equity awards granted			$ 40.4