CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 0.0	$ 14.4
Accounts receivable, less reserve of $1.0 and $1.5, respectively	221.2	188.7
Accounts receivable - unconsolidated affiliates	0.0	1.9
Accrued unbilled revenues	87.8	66.5
Income taxes receivable	7.8	5.8
Fuel inventories	81.1	84.3
Materials and supplies, at average cost	130.3	80.8
Other	32.6	54.6
Total current assets	560.8	497.0
OTHER PROPERTY AND INVESTMENTS
Investment in unconsolidated affiliates	1,153.6	1,160.4
Other	77.0	76.7
Total other property and investments	1,230.6	1,237.1
PROPERTY, PLANT AND EQUIPMENT
In service	11,544.6	11,041.2
Construction work in progress	566.0	867.5
Total property, plant and equipment	12,110.6	11,908.7
Less accumulated depreciation	3,637.5	3,568.8
Net property, plant and equipment	8,473.1	8,339.9
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	270.2	283.0
Other	8.9	55.7
Total deferred charges and other assets	279.1	338.7
TOTAL ASSETS	10,543.6	10,412.7
CURRENT LIABILITIES
Short-term debt	200.1	168.4
Accounts payable	161.4	230.4
Dividends payable	66.4	66.4
Customer deposits	82.5	80.7
Accrued taxes	42.9	44.5
Accrued interest	44.0	44.0
Accrued compensation	37.7	35.9
Long-term debt due within one year	499.9	249.8
Fuel clause over recoveries	38.7	1.7
Other	76.7	28.7
Total current liabilities	1,250.3	950.5
LONG-TERM DEBT	2,500.4	2,749.6
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	188.4	192.7
Deferred income taxes	1,255.1	1,227.8
Regulatory liabilities	1,296.1	1,283.4
Other	163.2	157.6
Total deferred credits and other liabilities	2,902.8	2,861.5
Total liabilities	6,653.5	6,561.6
COMMITMENTS AND CONTINGENCIES (NOTE 13)
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,120.1	1,114.8
Retained earnings	2,792.3	2,759.5
Accumulated other comprehensive loss, net of tax	(22.3)	(23.2)
Total stockholders' equity	3,890.1	3,851.1
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 10,543.6	$ 10,412.7

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).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682