Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2011

Goodwill and Intangible Assets [Abstract]

Schedule of the balance of goodwill by segment and the activity occurring in the past two fiscal years

	Minerals and Materials		Environmental		Oilfield Services		Consolidated
Balance at December 31, 2009	$	18,426	$	21,762	$	30,968	$	71,156
Change in goodwill relating to:
Acquisitions		-		761		-		761
Foreign exchange translation		(225)		(783)		-		(1,008)
Total changes		(225)		(22)		-		(247)
Balance at December 31, 2010		18,201		21,740		30,968		70,909
Change in goodwill relating to:
Sale of business		-		(156)		-		(156)
Foreign exchange translation		(817)		(427)		-		(1,244)
Total changes		(817)		(583)		-		(1,400)
Balance at December 31, 2011		17,384		21,157		30,968		69,509

Schedule of the balance of intangible assets by segment and the activity occurring in the past two fiscal years

	December 31, 2011						December 31, 2010
	Gross Carrying Value		Accumulated Amortization		Net Carrying Value		Gross Carrying Value		Accumulated Amortization		Net Carrying Value
Intangibles subject to amortization:
Trademarks	$	1,623	$	(1,533)	$	90	$	1,690	$	(1,283)	$	407
Patents		6,890		(6,807)		83		6,824		(6,701)		123
Customer related assets		47,069		(19,678)		27,391		48,460		(16,710)		31,750
Non-compete agreements		2,153		(2,053)		100		2,195		(2,051)		144
Developed technology		4,040		(1,998)		2,042		4,040		(1,592)		2,448
Other		2,492		(1,672)		820		3,221		(1,587)		1,634
Subtotal		64,267		(33,741)		30,526		66,430		(29,924)		36,506
Intangibles not subject to amortization:
Trademarks and tradenames		6,084		-		6,084		6,084		-		6,084
Total		70,351		(33,741)		36,610		72,514		(29,924)		42,590

Schedule of estimate amortization expense of intangible assets for the future years

	Amount
2012	$	4,157
2013		3,913
2014		3,585
2015		3,414
2016		3,384