Goodwill Schedule of Goodwill Allocated to Reporting Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Beginning of the Period [Roll Forward]
Goodwill before impairment	$ 1,273,848
Accumulated impairment losses	(572,832)
Goodwill, net	701,016
Adjustments of previous acquisition	(197)
Effect of change in exchange rates	(17,604)
End of the Period [Roll Forward]
Goodwill before impairment	1,234,400
Accumulated impairment losses	(551,185)
Goodwill, net	683,215
Energy Operating Segment [Member]
Beginning of the Period [Roll Forward]
Goodwill before impairment	859,454
Accumulated impairment losses	(249,502)
Goodwill, net	609,952
Adjustments of previous acquisition	(197)
Effect of change in exchange rates	(15,174)
End of the Period [Roll Forward]
Goodwill before impairment	834,654
Accumulated impairment losses	(240,073)
Goodwill, net	594,581
Water Operating Segment [Member]
Beginning of the Period [Roll Forward]
Goodwill before impairment	414,394
Accumulated impairment losses	(323,330)
Goodwill, net	91,064
Adjustments of previous acquisition	0
Effect of change in exchange rates	(2,430)
End of the Period [Roll Forward]
Goodwill before impairment	399,746
Accumulated impairment losses	(311,112)
Goodwill, net	$ 88,634