Goodwill Schedule of Goodwill Allocated to Reporting Segments (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill beginning balance	$ 548,578,000us-gaap_Goodwill	$ 701,016,000us-gaap_Goodwill
Goodwill, Other Changes		3,958,000us-gaap_GoodwillOtherChanges
Goodwill impairment	(977,000)us-gaap_GoodwillImpairmentLoss	(173,249,000)us-gaap_GoodwillImpairmentLoss	0us-gaap_GoodwillImpairmentLoss
Effect of change in exchange rates	(46,781,000)us-gaap_GoodwillTranslationAdjustments	16,853,000us-gaap_GoodwillTranslationAdjustments
Goodwill before impairment	1,191,808,000us-gaap_GoodwillGross	1,318,271,000us-gaap_GoodwillGross	1,273,848,000us-gaap_GoodwillGross
Accumulated impairment losses	(690,988,000)	(769,693,000)	(572,832,000)
Goodwill ending balance	500,820,000us-gaap_Goodwill	548,578,000us-gaap_Goodwill	701,016,000us-gaap_Goodwill
Electricity Operating Segment [Member]
Goodwill [Line Items]
Goodwill beginning balance	60,232,000	226,209,000
Goodwill, Other Changes		3,958,000
Goodwill impairment	(977,000)	(173,249,000)
Effect of change in exchange rates	(3,568,000)	3,314,000
Goodwill before impairment	449,668,000	493,610,000	475,711,000
Accumulated impairment losses	(393,981,000)	(433,378,000)	(249,502,000)
Goodwill ending balance	55,687,000	60,232,000
Gas Operating Segment [Member]
Goodwill [Line Items]
Goodwill beginning balance	394,878,000	383,743,000
Goodwill, Other Changes		0
Goodwill impairment	0	0
Effect of change in exchange rates	(35,393,000)	11,135,000
Goodwill before impairment	359,485,000	394,878,000	383,743,000
Accumulated impairment losses	0	0	0
Goodwill ending balance	359,485,000	394,878,000
Water Operating Segment [Member]
Goodwill [Line Items]
Goodwill beginning balance	93,468,000	91,064,000
Goodwill, Other Changes		0
Goodwill impairment	0	0
Effect of change in exchange rates	(7,820,000)	2,404,000
Goodwill before impairment	382,655,000	429,783,000	414,394,000
Accumulated impairment losses	(297,007,000)	(336,315,000)	(323,330,000)
Goodwill ending balance	$ 85,648,000	$ 93,468,000

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of other (increase) decrease of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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