v3.25.2
Condensed Balance Sheets Parenthetical - USD ($)
shares in Millions, $ in Millions
Jun. 30, 2025
Dec. 31, 2024
Jun. 30, 2024
Assets      
Accumulated depreciation $ 5,417.0 $ 5,189.2 $ 5,009.8
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 114.6 115.7 117.5
Common stock, outstanding 114.6 115.7 117.5