v3.26.1
Recent Financing Transactions - SPPC (Details) - SPPC - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Junior Subordinated Debt, 6.375%, Due 2056 | Subsidiary, junior subordinated debt    
Debt Instrument [Line Items]    
Debt, face amount   $ 600
Stated interest rate   6.375%
Interest rate reset period   5 years
Secured Credit Facility, $400 Million, expiring June 2029 | Line of credit    
Debt Instrument [Line Items]    
Maximum borrowing capacity $ 400