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Components of Energy Supply Obligations (Detail) - USD ($)
$ in Millions
Jun. 30, 2024
Dec. 31, 2023
Jun. 30, 2023
Contractual Obligation [Line Items]      
Energy Supply Obligations-Current $ 8.6 $ 15.0 $ 13.9
Exchange Gas Obligation      
Contractual Obligation [Line Items]      
Energy Supply Obligations-Current 5.5 6.4 8.7
Renewable Energy Portfolio Standards      
Contractual Obligation [Line Items]      
Energy Supply Obligations-Current $ 3.1 $ 8.6 $ 5.2