FINANCING (Details ) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 item
Unsecured revolving credit facility
Short-Term Borrowings
Unsecured revolving credit facility	$ 200
Additional borrowing capacity	75
Number of extensions	2
Extension period	1 year
Facility fee is payable quarterly on the full amount of the commitments under the facility based on our current credit ratings (as a percent)	0.175%
Maximum percentage of total indebtedness to total capitalization under the financial covenants of the credit facility agreement	65.00%
Percentage of total indebtedness to total capitalization under the financial covenants of the credit facility agreement	52.00%
Aggregate amount of default on other indebtedness subject to cross-default under the terms of the credit facility.	25
Outstanding borrowings	0
Unsecured revolving credit facility \| Federal fund effective rate
Short-Term Borrowings
Margin over the base rate (as a percent)	0.50%
Unsecured revolving credit facility \| One month LIBOR
Short-Term Borrowings
Margin over the base rate (as a percent)	1.00%
Unsecured revolving credit facility \| LIBOR
Short-Term Borrowings
Margin over the base rate (as a percent)	1.025%
Letters of credit
Short-Term Borrowings
Unsecured revolving credit facility	20
Swingline loan
Short-Term Borrowings
Unsecured revolving credit facility	20
Commercial paper
Short-Term Borrowings
Amount of credit facility used to back up outstanding commercial paper borrowings	$ 53.0

Represents the period of extension to the maturity of debt instrument.

No definition available.

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- Definition

Represents the number of extensions to the maturity of debt instrument.

+ References

No definition available.

+ Details

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- Definition

Represents the facility fee that is payable quarterly on the full amount of the commitments under the facility based on the entity's current credit ratings.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of additional borrowing capacity under the credit facility.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of the borrowing capacity under the credit facility used to back up outstanding commercial paper borrowings.

+ References

No definition available.

+ Details

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- Definition

Represents the aggregate amount of default by the entity on other indebtedness subject to the cross-default provisions of the credit facility agreement.

+ References

No definition available.

+ Details

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- Definition

Represents of Line Of Credit Facility Debt To Capital Ratio Covenant Compliance

+ References

No definition available.

+ Details

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- Definition

Represents the maximum debt to capital ratio allowable under the financial covenant.

+ References

No definition available.

+ Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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