Fair Value (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Recurring Fair Value Measures [Table Text Block]

	Fair Value as of December 31, 2022
Recurring Fair Value Measures	Level 1	Level 2	Level 3	Total
Millions
Assets:
Investments (a)
Available-for-sale – Equity Securities	$7.7	—	—	$7.7
Available-for-sale – Corporate and Governmental Debt Securities (b)	—	$5.7	—	5.7
Cash Equivalents	4.2	—	—	4.2
Total Fair Value of Assets	$11.9	$5.7	—	$17.6
Liabilities:
Deferred Compensation (c)	—	$15.0	—	$15.0
Total Fair Value of Liabilities	—	$15.0	—	$15.0

(a)Included in Other Non-Current Assets on the Consolidated Balance Sheet.

(b)As of December 31, 2022, the aggregate amount of available-for-sale corporate and governmental debt securities maturing in one year or less was $0.7 million, in one year to less than three years was $2.7 million, in three years to less than five years was $1.9 million and in five or more years was $0.4 million.

(c)Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.

	Fair Value as of December 31, 2021
Recurring Fair Value Measures	Level 1	Level 2	Level 3	Total
Millions
Assets:
Investments (a)
Available-for-sale – Equity Securities	$8.9	—	—	$8.9
Available-for-sale – Corporate and Governmental Debt Securities	—	$6.2	—	6.2
Cash Equivalents	2.5	—	—	2.5
Total Fair Value of Assets	$11.4	$6.2	—	$17.6
Liabilities: (b)
Deferred Compensation	—	$18.0	—	$18.0
Total Fair Value of Liabilities	—	$18.0	—	$18.0

(a)Included in Other Non-Current Assets on the Consolidated Balance Sheet.

(b)Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.

Financial Instruments [Table Text Block]

Financial Instruments	Carrying Amount	Fair Value
Millions
Short-Term and Long-Term Debt (a)
December 31, 2022	$1,929.1	$1,782.7
December 31, 2021	$1,986.4	$2,192.6

(a) Excludes unamortized debt issuance costs.