Segment Information Information By Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Revenues	$ 482,175	$ 579,140	$ 929,711	$ 1,150,780
Gross profit	159,588	196,745	299,711	379,850
Operating Income (Loss)	17,976	46,063	20,323	85,684
Total other income (expense)	(3,884)	(3,208)	(5,978)	(7,628)
Income Before Income Taxes	14,092	42,855	14,345	78,056
Energy Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	349,623	444,598	662,301	882,345
Gross profit	112,673	148,951	208,227	283,554
Operating Income (Loss)	14,764	47,069	15,244	85,233
Water Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	132,552	134,542	267,410	268,435
Gross profit	46,915	47,794	91,484	96,296
Operating Income (Loss)	15,389	11,666	27,964	27,603
Corporate Unallocated [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (12,177)	$ (12,672)	$ (22,885)	$ (27,152)