Segment Information Information By Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 448,247us-gaap_SalesRevenueNet	$ 474,795us-gaap_SalesRevenueNet
Gross profit	138,199us-gaap_GrossProfit	154,535us-gaap_GrossProfit
Operating Income (Loss)	13,539us-gaap_OperatingIncomeLoss	4,539us-gaap_OperatingIncomeLoss
Total other income (expense)	(2,611)us-gaap_NonoperatingIncomeExpense	(5,310)us-gaap_NonoperatingIncomeExpense
Income Before Income Taxes	10,928	(771)
Electricity Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	193,852	180,218
Gross profit	55,120	42,740
Operating Income (Loss)	2,396	(22,969)
Gas Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	125,089	146,109
Gross profit	43,516	58,406
Operating Income (Loss)	13,592	25,724
Water Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	129,306	148,468
Gross profit	39,563	53,389
Operating Income (Loss)	8,097	20,643
Corporate Unallocated [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (10,546)	$ (18,859)

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

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+ References

No definition available.

+ Details

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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