Goodwill Schedule of Goodwill Allocated to Reporting Segments (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Goodwill [Line Items]
Goodwill before impairment	$ 1,201,767	$ 1,221,757
Accumulated impairment losses	(537,327)	(584,847)
Goodwill, net	664,440	636,910
Goodwill, Acquired During Period	42,620
Effect of change in exchange rates	(15,090)
Energy Operating Segment [Member]
Goodwill [Line Items]
Goodwill before impairment	812,057	808,601
Accumulated impairment losses	(234,037)	(254,735)
Goodwill, net	578,020	553,866
Goodwill, Acquired During Period	42,620
Effect of change in exchange rates	(18,466)
Water Operating Segment [Member]
Goodwill [Line Items]
Goodwill before impairment	389,710	413,156
Accumulated impairment losses	(303,290)	(330,112)
Goodwill, net	86,420	83,044
Goodwill, Acquired During Period	0
Effect of change in exchange rates	$ 3,376