Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 24.8	$ 37.5
Accounts receivable and unbilled revenues, net of reserves of $220.1 and $140.0, respectively	1,202.8	1,176.5
Materials, supplies, and inventories	528.6	549.8
Prepayments	263.4	261.8
Other	63.4	68.0
Current assets	2,083.0	2,093.6
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $9,364.7 and $8,878.7, respectively	25,707.4	23,620.1
Regulatory assets	3,524.1	3,506.7
Equity investment in transmission affiliates	1,764.3	1,720.8
Goodwill	3,052.8	3,052.8
Other	896.5	957.8
Long-term assets	34,945.1	32,858.2
Total assets	37,028.1	34,951.8
Current liabilities
Short-term debt	1,776.9	830.8
Current portion of long-term debt	785.8	693.2
Accounts payable	880.7	908.1
Accrued payroll and benefits	174.0	199.8
Other	530.7	550.8
Current liabilities	4,148.1	3,182.7
Long-term liabilities
Long-term debt	11,728.1	11,211.0
Deferred income taxes	4,059.8	3,769.3
Deferred revenue, net	412.2	497.1
Regulatory liabilities	3,928.1	3,992.8
Environmental remediation liabilities	532.9	589.2
Pension and OPEB obligations	327.0	326.2
Other	1,229.4	1,128.9
Long-term liabilities	22,217.5	21,514.5
Commitments and contingencies (Note 24)
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	4,143.7	4,186.6
Retained earnings	6,329.6	5,927.7
Accumulated other comprehensive loss	(6.8)	(4.1)
Common shareholders' equity	10,469.7	10,113.4
Preferred stock of subsidiary	30.4	30.4
Noncontrolling interests	162.4	110.8
Total liabilities and equity	$ 37,028.1	$ 34,951.8