CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 20.0	$ 84.5
Accounts receivable and unbilled revenues, net of reserves of $137.8 and $149.2, respectively	911.8	1,280.9
Materials, supplies, and inventories	593.3	548.2
Prepayments	166.1	256.8
Other	81.8	77.2
Current assets	1,773.0	2,247.6
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $8,807.7 and $8,636.6, respectively	23,035.1	22,000.9
Regulatory assets	3,999.9	3,805.1
Equity investment in transmission affiliates	1,720.4	1,665.3
Goodwill	3,052.8	3,052.8
Other	796.0	704.1
Long-term assets	32,604.2	31,228.2
Total assets	34,377.2	33,475.8
Current liabilities
Short-term debt	686.4	1,440.1
Current portion of long-term debt	692.6	365.0
Accounts payable	769.0	876.4
Accrued payroll and benefits	167.0	185.4
Other	503.4	464.8
Current liabilities	2,818.4	3,331.7
Long-term liabilities
Long-term debt	10,897.3	9,994.0
Deferred income taxes	3,613.8	3,388.1
Deferred revenue, net	502.8	520.4
Regulatory liabilities	4,198.8	4,251.6
Environmental remediation liabilities	631.8	616.4
Pension and OPEB obligations	411.5	422.8
Other	1,116.4	1,108.1
Long-term liabilities	21,372.4	20,301.4
Commitments and contingencies (Note 21)
Common shareholders' equity
Common stock – $0.01 par value; 325,000,000 shares authorized; 315,435,595 and 315,523,192 shares outstanding, respectively	3.2	3.2
Additional paid in capital	4,185.0	4,250.1
Retained earnings	5,869.9	5,538.2
Accumulated other comprehensive loss	(7.1)	(2.6)
Common shareholders' equity	10,051.0	9,788.9
Preferred stock of subsidiary	30.4	30.4
Noncontrolling interests	105.0	23.4
Total liabilities and equity	$ 34,377.2	$ 33,475.8