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Fair Value - Recurring Fair Value Measures (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Liabilities:
Aggregate amount of available-for-sale corporate and governmental debt securities maturing in one year or less	$ 1.3
Aggregate amount of available-for-sale corporate and governmental debt securities maturing in one year to less than three years	3.2
Aggregate amount of available-for-sale corporate and governmental debt securities maturing in three years to less than five years	1.0
Aggregate amount of available-for-sale corporate and governmental debt securities maturing in five years or more	0.5
Recurring Fair Value Measures
Investments [Abstract]
Available-for-sale – Equity Securities	8.7	$ 7.7
Available-for-sale – Corporate and Governmental Debt Securities	6.0	5.7
Cash Equivalents	5.8	4.2
Total Fair Value of Assets	20.5	17.6
Liabilities:
Deferred Compensation	16.5	15.0
Total Fair Value of Liabilities	16.5	15.0
Recurring Fair Value Measures | Level 1
Investments [Abstract]
Available-for-sale – Equity Securities	8.7	7.7
Available-for-sale – Corporate and Governmental Debt Securities	0.0	0.0
Cash Equivalents	5.8	4.2
Total Fair Value of Assets	14.5	11.9
Liabilities:
Deferred Compensation	0.0	0.0
Total Fair Value of Liabilities	0.0	0.0
Recurring Fair Value Measures | Level 2
Investments [Abstract]
Available-for-sale – Equity Securities	0.0	0.0
Available-for-sale – Corporate and Governmental Debt Securities	6.0	5.7
Cash Equivalents	0.0	0.0
Total Fair Value of Assets	6.0	5.7
Liabilities:
Deferred Compensation	16.5	15.0
Total Fair Value of Liabilities	16.5	15.0
Recurring Fair Value Measures | Level 3
Investments [Abstract]
Available-for-sale – Equity Securities	0.0	0.0
Available-for-sale – Corporate and Governmental Debt Securities	0.0	0.0
Cash Equivalents	0.0	0.0
Total Fair Value of Assets	0.0	0.0
Liabilities:
Deferred Compensation	0.0	0.0
Total Fair Value of Liabilities	$ 0.0	$ 0.0

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Amount of available-for-sale debt securities at fair value maturing in after the fifth fiscal year following the latest fiscal year (maturing in five years or more).

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Amount of available-for-sale debt securities at fair value maturing after the first fiscal year through the third fiscal year following the latest fiscal year (maturing in more than one year to less than three years).

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Amount of available-for-sale debt securities at fair value maturing after the third fiscal year through the fifth fiscal year following the latest fiscal year (maturing in three years to less than five years).

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as noncurrent.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as noncurrent.

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Fair value of financial and nonfinancial obligations.

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Amount of noncurrent assets that are pledged or subject to withdrawal restrictions, classified as other.

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