Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 37.5	$ 84.5
Accounts receivable and unbilled revenues, net of reserves of $140.0 and $149.2, respectively	1,176.5	1,280.9
Materials, supplies, and inventories	549.8	548.2
Prepayments	261.8	256.8
Other	68.0	77.2
Current assets	2,093.6	2,247.6
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $8,878.7 and $8,636.6, respectively	23,620.1	22,000.9
Regulatory assets	3,506.7	3,805.1
Equity investment in transmission affiliates	1,720.8	1,665.3
Goodwill	3,052.8	3,052.8
Other	957.8	704.1
Long-term assets	32,858.2	31,228.2
Total assets	34,951.8	33,475.8
Current liabilities
Short-term debt	830.8	1,440.1
Current portion of long-term debt	693.2	365.0
Accounts payable	908.1	876.4
Accrued payroll and benefits	199.8	185.4
Other	550.8	464.8
Current liabilities	3,182.7	3,331.7
Long-term liabilities
Long-term debt	11,211.0	9,994.0
Deferred income taxes	3,769.3	3,388.1
Deferred revenue, net	497.1	520.4
Regulatory liabilities	3,992.8	4,251.6
Environmental remediation liabilities	589.2	616.4
Pension and OPEB obligations	326.2	422.8
Other	1,128.9	1,108.1
Long-term liabilities	21,514.5	20,301.4
Commitments and contingencies (Note 23)
Common shareholders' equity
Common stock – $0.01 par value; 325,000,000 shares authorized; 315,434,531 and 315,523,192 shares outstanding, respectively	3.2	3.2
Additional paid in capital	4,186.6	4,250.1
Retained earnings	5,927.7	5,538.2
Accumulated other comprehensive loss	(4.1)	(2.6)
Common shareholders' equity	10,113.4	9,788.9
Preferred stock of subsidiary	30.4	30.4
Noncontrolling interests	110.8	23.4
Total liabilities and equity	$ 34,951.8	$ 33,475.8