Condensed Balance Sheets Parenthetical - USD ($) shares in Millions, $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024
Assets
Accumulated depreciation	$ 5,291.8	$ 5,189.2	$ 4,917.5
Shareholders' equity:
Common stock, par value	$ 1.00	$ 1.00	$ 1.00
Common stock, authorized (in shares)	240.0	240.0	240.0
Common stock, issued	115.1	115.7	119.4
Common stock, outstanding	115.1	115.7	119.4

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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