Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 37.5	$ 49.8
Accounts receivable and unbilled revenues, net of reserves of $108.0 and $113.3, respectively	1,241.7	1,028.6
Materials, supplies and inventories	587.6	687.0
Assets held for sale	0.0	96.8
Prepayments	204.4	285.8
Other	97.5	58.8
Current assets	2,168.7	2,206.8
Long-term assets
Property, plant, and equipment, net of accumulated depreciation of $8,214.6 and $7,919.1, respectively	19,915.5	19,189.7
Regulatory assets	3,087.9	3,064.6
Equity investment in transmission affiliate	1,443.9	1,380.9
Goodwill	3,046.2	3,023.5
Other	461.0	489.7
Long-term assets	27,954.5	27,148.4
Total assets	30,123.2	29,355.2
Current liabilities
Short-term debt	860.2	1,095.0
Current portion of long-term debt	157.2	157.7
Accounts payable	861.5	815.4
Accrued payroll and benefits	163.8	169.7
Other	388.9	471.2
Current liabilities	2,431.6	2,709.0
Long-term liabilities
Long-term debt	9,158.2	9,124.1
Deferred income taxes	5,146.6	4,622.3
Deferred revenue, net	566.2	579.4
Regulatory liabilities	1,563.8	1,392.2
Environmental remediation liabilities	633.6	628.2
Pension and other postretirement benefit obligations	498.6	543.1
Other	1,164.4	1,071.7
Long-term liabilities	18,731.4	17,961.0
Commitments and Contingencies (Note 18)
Common shareholders' equity
Common stock - $0.01 par value; 325,000,000 shares authorized; 315,614,941 and 315,683,496 shares outstanding, respectively	3.2	3.2
Additional paid in capital	4,309.8	4,347.2
Retained earnings	4,613.9	4,299.8
Accumulated other comprehensive income	2.9	4.6
Common shareholders' equity	8,929.8	8,654.8
Preferred stock of subsidiary	30.4	30.4
Total liabilities and equity	$ 30,123.2	$ 29,355.2

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.