Property, Plant, and Equipment - Balances (Details) $ in Millions	Dec. 31, 2024 USD ($)	May 31, 2024 MW	Dec. 31, 2023 USD ($)	Jun. 30, 2023 MW
Property, plant, and equipment
Accumulated depreciation	$ 11,611.9		$ 11,073.1
Net property, plant, and equipment	34,645.4		31,581.5
WE | West Riverside Energy Center
Property, plant, and equipment
Capacity of generation unit | MW		100		100
OCPP Units 7 and 8 | WE
Property, plant, and equipment
Net book value of plant to be retired	657.4
Columbia Units 1 and 2 | WPS
Property, plant, and equipment
Net book value of plant to be retired	248.9
Regulated operations
Property, plant, and equipment
Accumulated depreciation	9,411.0		8,907.9
Net	25,854.3		24,215.3
CWIP	1,653.6		1,118.3
Net property, plant, and equipment	27,507.9		25,333.6
Regulated operations | Electric - generation
Property, plant, and equipment
Property, plant, and equipment	6,976.3		6,190.4
Regulated operations | Electric - distribution
Property, plant, and equipment
Property, plant, and equipment	9,298.9		8,688.0
Regulated operations | Natural gas - distribution, storage, and transmission
Property, plant, and equipment
Property, plant, and equipment	15,673.0		14,851.3
Regulated operations | Property, plant, and equipment to be retired, net
Property, plant, and equipment
Property, plant, and equipment to be retired, net	906.3		1,043.5
Regulated operations | Other
Property, plant, and equipment
Property, plant, and equipment	2,410.8		2,350.0
Non-regulated operations
Property, plant, and equipment
Accumulated depreciation	1,393.9		1,227.5
Net	7,096.2		6,211.8
CWIP	41.3		36.1
Net property, plant, and equipment	7,137.5		6,247.9
Non-regulated operations | Other
Property, plant, and equipment
Property, plant, and equipment	14.1		14.3
Non-regulated operations | We Power generation
Property, plant, and equipment
Property, plant, and equipment	3,284.3		3,295.9
Non-regulated operations | Renewable generation
Property, plant, and equipment
Property, plant, and equipment	4,720.8		3,667.7
Non-regulated operations | Natural gas storage
Property, plant, and equipment
Property, plant, and equipment	298.6		291.6
Non-regulated operations | Corporate services
Property, plant, and equipment
Property, plant, and equipment	172.3		169.8
Non-Utility Energy Infrastructure | Non-regulated operations
Property, plant, and equipment
Property, plant, and equipment	$ 8,303.7		$ 7,255.2