Stock-Based Compensation (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) item $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Stock-based compensation
Total unrecognized compensation cost related to the unvested awards	$ 17.9
Total weighted average remaining term of unrecognized compensation costs	1 year 6 months 18 days
Compensation cost recognized	$ 21.2	$ 19.5	$ 20.2
Class A
Stock-based compensation
Shares available for future grants of new equity awards | shares	764,240
Performance stock units
Stock-based compensation
Granted (in shares) | shares	67,000	79,000	99,000
Total unrecognized compensation cost related to the unvested awards	$ 11.2
Total weighted average remaining term of unrecognized compensation costs	1 year 6 months 4 days
Compensation cost recognized	$ 10.4	$ 7.5	$ 9.7
Fair value assumptions
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 179.19	$ 162.23	$ 106.37
Performance stock units | Class A
Weighted Average Intrinsic Value
Company's closing Common Stock price (in dollars per share) | $ / shares	$ 276.02
2004 Stock Incentive Plan
Stock-based compensation
Number of stock incentive plans | item	1
2004 Stock Incentive Plan | Restricted Stock and Deferred Shares
Stock-based compensation
Vesting period	3 years
Percentage of stock options becoming exercisable	33.00%
2004 Stock Incentive Plan | Performance Shares and Deferred Shares
Stock-based compensation
Minimum service period	10 years
Minimum age	55 years
2004 Stock Incentive Plan | Performance stock units
Stock-based compensation
Vesting period	3 years
Period of time used to calculate the compound annual growth rate	3 years
2004 Stock Incentive Plan | Performance stock units | Minimum
Stock-based compensation
Percent of target shares a recipient may earn	0
2004 Stock Incentive Plan | Performance stock units | Maximum
Stock-based compensation
Percent of target shares a recipient may earn	2
Management Stock Purchase Plan | Maximum
Stock-based compensation
Percentage of annual incentive bonus that may be used to purchase RSU's		50.00%
Management Stock Purchase Plan | Class A
Stock-based compensation
Purchase price as percentage of fair market value of common stock on grant date		80.00%
Purchase price of common stock, discount percent	20.00%
Shares authorized | shares	2,000,000
Shares available for future grants of new equity awards | shares	677,258
Management Stock Purchase Plan | Restricted stock units (RSUs)
Stock-based compensation
Granted (in shares) | shares	18,000	20,000	26,000
Purchase price of common stock, discount percent	20.00%
Minimum deferral period		3 years
Total unrecognized compensation cost related to the unvested awards	$ 1.4
Total weighted average remaining term of unrecognized compensation costs	1 year 4 months 28 days
Compensation cost recognized	$ 1.2	$ 1.3	$ 1.2
Weighted Average Intrinsic Value
Company's closing Common Stock price (in dollars per share) | $ / shares	$ 276.02
Fair value assumptions
Expected life (years)	3 years	3 years
Expected stock price volatility (as a percent)	27.30%	28.90%
Expected dividend yield (as a percent)	0.90%	0.80%
Risk-free interest rate (as a percent)	4.00%	4.50%
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 67.63	$ 68.94	$ 57.5
Management Stock Purchase Plan | Restricted stock units (RSUs) | Minimum
Stock-based compensation
Vesting period		3 years