Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 38.9	$ 37.5
Accounts receivable and unbilled revenues, net of reserves of $143.2 and $108.0, respectively	1,350.7	1,241.7
Materials, supplies, and inventories	539.0	587.6
Prepayments	210.0	204.4
Other	74.9	97.5
Current assets	2,213.5	2,168.7
Long-term assets
Property, plant, and equipment, net of accumulated depreciation of $8,618.5 and $8,214.6, respectively	21,347.0	19,915.5
Regulatory assets	2,803.2	3,087.9
Equity investment in transmission affiliates	1,553.4	1,443.9
Goodwill	3,053.5	3,046.2
Other	619.9	461.0
Long-term assets	29,377.0	27,954.5
Total assets	31,590.5	30,123.2
Current liabilities
Short-term debt	1,444.6	860.2
Current portion of long-term debt	842.1	157.2
Accounts payable	859.9	861.5
Accrued payroll and benefits	169.1	163.8
Other	553.6	388.9
Current liabilities	3,869.3	2,431.6
Long-term liabilities
Long-term debt	8,746.6	9,158.2
Deferred income taxes	2,999.8	5,146.6
Deferred revenue, net	543.3	566.2
Regulatory liabilities	3,718.6	1,563.8
Environmental remediation liabilities	617.4	633.6
Pension and OPEB obligations	397.4	498.6
Other	1,206.3	1,164.4
Long-term liabilities	18,229.4	18,731.4
Commitments and Contingencies (Note 21)
Common shareholders' equity
Common stock - $0.01 par value; 325,000,000 shares authorized; 315,574,624 and 315,614,941 shares outstanding, respectively	3.2	3.2
Additional paid in capital	4,278.5	4,309.8
Retained earnings	5,176.8	4,613.9
Accumulated other comprehensive income	2.9	2.9
Common shareholders' equity	9,461.4	8,929.8
Preferred stock of subsidiary	30.4	30.4
Total liabilities and equity	$ 31,590.5	$ 30,123.2

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.