DISPOSAL AND RELATED TRANSACTIONS DISPOSAL AND RELATED TRANSACTIONS - SUGS Contribution (Details) (SUGS Contribution [Member], USD $) In Millions, unless otherwise specified	1 Months Ended
Feb. 28, 2013
Business Acquisition [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	31.4
Regency Class F Units to be Issued in SUGS Contribution	6.3
Southern Union [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Current Assets, Cash and Cash Equivalents	570
Estimated Closing Adjustments	107
ETP [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Current Assets, Cash and Cash Equivalents	30

The amount of cash consideration adjusted for closing adjustments related to a business acquisition.

No definition available.

Name:	sug_EstimatedClosingAdjustments
Namespace Prefix:	sug_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of Regency class F units to be Issued in connection with the SUGS Contribution.

+ References

No definition available.

+ Details

Name:	sug_RegencyClassFUnitsToBeIssuedInSugsContribution
Namespace Prefix:	sug_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares of equity interests issued or issuable to acquire entity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cash and cash equivalents acquired in a business combination.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant