CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 33.8	$ 16.3
Accounts receivable and unbilled revenues, net of reserves of $200.6 and $198.3, respectively	1,635.7	1,505.7
Materials, supplies, and inventories	368.8	635.8
Prepayments	172.9	245.5
Derivative assets	204.3	107.0
Other	147.1	146.4
Current assets	2,562.6	2,656.7
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $10,041.4 and $9,889.3, respectively	27,110.2	26,982.4
Regulatory assets (March 31, 2022 and December 31, 2021 include $98.2 and $100.7, respectively, related to WEPCo Environmental Trust)	3,163.6	3,264.8
Equity investment in transmission affiliates	1,818.2	1,789.4
Goodwill	3,052.8	3,052.8
Pension and OPEB assets	910.2	881.3
Other	356.9	361.1
Long-term assets	36,411.9	36,331.8
Total assets	38,974.5	38,988.5
Current liabilities
Short-term debt	1,450.0	1,897.0
Current portion of long-term debt (March 31, 2022 and December 31, 2021 include $8.8, related to WEPCo Environmental Trust)	163.4	169.4
Accounts payable	693.7	1,005.7
Other	957.3	680.9
Current liabilities	3,264.4	3,753.0
Long-term liabilities
Long-term debt (March 31, 2022 and December 31, 2021 include $102.8 and $102.7, respectively, related to WEPCo Environmental Trust)	13,514.3	13,523.7
Deferred income taxes	4,426.2	4,308.5
Deferred revenue, net	383.8	389.2
Regulatory liabilities	4,032.6	3,946.0
Environmental remediation liabilities	517.2	532.6
Pension and OPEB obligations	218.5	219.0
Other	1,173.0	1,203.2
Long-term liabilities	24,265.6	24,122.2
Commitments and contingencies (Note 19)
Common shareholders' equity
Common stock – $0.01 par value; 325,000,000 shares authorized; 315,434,531 shares outstanding	3.2	3.2
Additional paid in capital	4,131.8	4,138.1
Retained earnings	7,111.4	6,775.1
Accumulated other comprehensive loss	(3.2)	(3.2)
Common shareholders' equity	11,243.2	10,913.2
Preferred stock of subsidiary	30.4	30.4
Noncontrolling interests	170.9	169.7
Total liabilities and equity	$ 38,974.5	$ 38,988.5