Basis of Presentation (Details) (USD $)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2013 retail_customers	Jun. 30, 2012	Jun. 30, 2013 retail_customers	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Basis of Presentation [Abstract]
Number of Retail Customers	833,750		833,750
Decoupling Mechanism Deferrals, Net		$ 4,000,000	$ (5,000,000)	$ 4,000,000
Other Comprehensive Income	0	0	0	0
revenue overstatment	$ 9,000,000			$ 3,000,000	$ 3,000,000	$ 2,000,000	$ 1,000,000

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569643-111683

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

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-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

+ Details