Segment Information Information By Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 447,536	$ 571,640
Gross profit	140,123	183,105
Operating Income (Loss)	2,347	39,621
Total other income (expense)	(2,094)	(4,420)
Income Before Income Taxes	253	35,201
Energy Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	312,678	437,747
Gross profit	95,554	134,603
Operating Income (Loss)	480	38,164
Water Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	134,858	133,893
Gross profit	44,569	48,502
Operating Income (Loss)	12,575	15,937
Corporate Unallocated [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (10,708)	$ (14,480)