FAIR VALUE - Recurring Fair Value Measures (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Liabilities
Aggregate amount of available-for-sale corporate and governmental debt securities maturing in one year	$ 2.2
Aggregate amount of available-for-sale corporate and governmental debt securities maturing after one year through three years	2.3
Aggregate amount of available-for-sale corporate and governmental debt securities maturing after one year through three years after three years through five years	1.7
Aggregate amount of available-for-sale corporate and governmental debt securities maturing after one year through three years after three years through five years after five years	0.5
Recurring Fair Value Measures
Investments
Available-for-sale – Equity Securities	9.2	$ 8.7
Available-for-sale – Corporate and Governmental Debt Securities	6.7	6.0
Cash Equivalents	7.5	5.8
Total Fair Value of Assets	23.4	20.5
Liabilities
Deferred Compensation	20.5	16.5
Total Fair Value of Liabilities	20.5	16.5
Recurring Fair Value Measures | Level 1
Investments
Available-for-sale – Equity Securities	9.2	8.7
Available-for-sale – Corporate and Governmental Debt Securities	0.0	0.0
Cash Equivalents	7.5	5.8
Total Fair Value of Assets	16.7	14.5
Liabilities
Deferred Compensation	0.0	0.0
Total Fair Value of Liabilities	0.0	0.0
Recurring Fair Value Measures | Level 2
Investments
Available-for-sale – Equity Securities	0.0	0.0
Available-for-sale – Corporate and Governmental Debt Securities	6.7	6.0
Cash Equivalents	0.0	0.0
Total Fair Value of Assets	6.7	6.0
Liabilities
Deferred Compensation	20.5	16.5
Total Fair Value of Liabilities	20.5	16.5
Recurring Fair Value Measures | Level 3
Investments
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