Fair Value Measurements (Debt Instruments) (Details) $ in Millions	Sep. 30, 2026 USD ($)
$500.0 million Fixed Rate Notes Due June 2028
Debt instrument, face amount	$ 500.0
$750.0 million Fixed Rate Notes Due March 2030
Debt instrument, face amount	750.0
$750.0 million Fixed Rate Notes Due March 2032
Debt instrument, face amount	750.0
$750.0 million Fixed Rate Notes Due September 2043
Debt instrument, face amount	750.0
$700.0 million Fixed Rate Notes Due June 2048
Debt instrument, face amount	700.0
Level 2 \| $500.0 million Fixed Rate Notes Due June 2028
Fair Value	489.9
Level 2 \| $750.0 million Fixed Rate Notes Due March 2030
Fair Value	727.8
Level 2 \| $750.0 million Fixed Rate Notes Due March 2032
Fair Value	649.7
Level 2 \| $750.0 million Fixed Rate Notes Due September 2043
Fair Value	685.3
Level 2 \| $700.0 million Fixed Rate Notes Due June 2048
Fair Value	$ 549.7

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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+ Details