Property, Plant, and Equipment - Balances (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, plant, and equipment
Accumulated depreciation	$ 8,878.7	$ 8,515.9
Net property, plant, and equipment	23,620.1	22,000.9
Utility operations
Property, plant, and equipment
Accumulated depreciation	8,073.7	7,573.6
Net	19,102.6	17,961.8
CWIP	820.4	707.5
Net property, plant, and equipment	19,923.0	18,669.3
Utility operations \| Electric - generation
Property, plant, and equipment
Property, plant, and equipment	6,858.8	6,410.6
Utility operations \| Electric - distribution
Property, plant, and equipment
Property, plant, and equipment	7,018.1	6,534.6
Utility operations \| Natural gas - distribution, storage, and transmission
Property, plant, and equipment
Property, plant, and equipment	11,602.7	10,766.3
Utility operations \| Property, plant, and equipment to be retired, net
Property, plant, and equipment
Property, plant, and equipment to be retired, net	0.0	174.8
Utility operations \| Other
Property, plant, and equipment
Property, plant, and equipment	1,696.7	1,649.1
Non-utility operations
Property, plant, and equipment
Accumulated depreciation	805.0	731.5
Net	3,672.3	3,249.1
CWIP	24.8	82.5
Net property, plant, and equipment	3,697.1	3,331.6
Non-utility operations \| Other
Property, plant, and equipment
Property, plant, and equipment	88.8	127.1
Non-utility operations \| We Power generation
Property, plant, and equipment
Property, plant, and equipment	3,245.7	3,244.4
Non-utility operations \| Renewable generation
Property, plant, and equipment
Property, plant, and equipment	716.5	193.3
Non-utility operations \| Natural gas storage
Property, plant, and equipment
Property, plant, and equipment	245.9	244.8
Non-utility operations \| Corporate services
Property, plant, and equipment
Property, plant, and equipment	180.4	171.0
Non-Utility Energy Infrastructure \| Non-utility operations
Property, plant, and equipment
Property, plant, and equipment	$ 4,208.1	$ 3,682.5

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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