CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 30.6	$ 84.5
Accounts receivable and unbilled revenues, net of reserves of $163.2 and $149.2, respectively	1,430.1	1,280.9
Materials, supplies, and inventories	330.1	548.2
Prepayments	167.2	256.8
Other	50.3	77.2
Current assets	2,008.3	2,247.6
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $8,589.0 and $8,636.6, respectively	22,193.3	22,000.9
Regulatory assets	4,009.8	3,805.1
Equity investment in transmission affiliates	1,670.6	1,665.3
Goodwill	3,052.8	3,052.8
Other	802.3	704.1
Long-term assets	31,728.8	31,228.2
Total assets	33,737.1	33,475.8
Current liabilities
Short-term debt	1,145.2	1,440.1
Current portion of long-term debt	366.0	365.0
Accounts payable	674.1	876.4
Accrued payroll and benefits	125.9	185.4
Other	578.7	464.8
Current liabilities	2,889.9	3,331.7
Long-term liabilities
Long-term debt	10,326.7	9,994.0
Deferred income taxes	3,459.9	3,388.1
Deferred revenue, net	514.5	520.4
Regulatory liabilities	4,274.3	4,251.6
Environmental remediation liabilities	631.8	616.4
Pension and OPEB obligations	418.1	422.8
Other	1,109.8	1,108.1
Long-term liabilities	20,735.1	20,301.4
Commitments and contingencies (Note 20)
Common shareholders' equity
Common stock – $0.01 par value; 325,000,000 shares authorized; 315,438,398 and 315,523,192 shares outstanding, respectively	3.2	3.2
Additional paid in capital	4,213.2	4,250.1
Retained earnings	5,772.1	5,538.2
Accumulated other comprehensive loss	(4.0)	(2.6)
Common shareholders' equity	9,984.5	9,788.9
Preferred stock of subsidiary	30.4	30.4
Noncontrolling interests	97.2	23.4
Total liabilities and equity	$ 33,737.1	$ 33,475.8