v3.26.1
Summary of Significant Accounting Policies - Components of Accrued Revenue (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Deferred Revenue Arrangement [Line Items]      
Regulatory Assets – Current [1] $ 64.8 $ 78.1 $ 52.6
Total Accrued Revenue 69.5 87.0 56.8
Regulatory Assets      
Deferred Revenue Arrangement [Line Items]      
Regulatory Assets – Current 64.8 78.1 52.6
Unbilled Revenues      
Deferred Revenue Arrangement [Line Items]      
Regulatory Assets – Current $ 4.7 $ 8.9 $ 4.2
[1] Reflects amounts included in the Accrued Revenue on the Company’s Consolidated Balance Sheets.