4.	Composition of Certain Financial Statement Captions

Inventories are valued at the lower of cost (first in, first out) or market. Inventory costs include the cost of material, labor and manufacturing overhead. The following is a summary of the inventory components as of March 31, 2012 and December 31, 2011 (in thousands):

	March 31, 2012		December 31, 2011
Raw materials	$	8,994	$	8,533
Work-in-process		82,606		65,645
Finished goods		44,336		43,095
	$	135,936	$	117,273

Property, plant and equipment are recorded at cost and consist of the following (in thousands):

	March 31, 2012			December 31, 2011
Land	$	18,811		$	18,550
Buildings and improvements		119,519			117,961
Machinery and equipment		237,957			233,702
Leasehold improvements		8,514			8,482
Office equipment		38,762			37,906
Construction in progress		14,134			11,961
		437,697			428,562
Less accumulated depreciation and amortization		(193,651	)		(185,186	)
	$	244,046		$	243,376

The components of intangible assets are as follows (in thousands):

	March 31, 2012						December 31, 2011
	Gross Amount		Accumulated Amortization		Net Amount		Gross Amount		Accumulated Amortization		Net Amount
Amortizing Intangible Assets
Backlog	$	1,824	$	1,824	$	-	$	1,808	$	1,808	$	-
Developed technology		70,739		7,758		62,981		70,590		7,233		63,357
Tradename		4,110		722		3,388		4,110		698		3,412
Customer relationships		47,604		16,944		30,660		47,604		16,212		31,392
Non-compete agreement		1,100		775		325		1,100		775		325
Non-amortizing tradename		2,269		-		2,269		2,204		-		2,204
Total	$	127,646	$	28,023	$	99,623	$	127,416	$	26,726	$	100,690

The estimated useful lives for intangible assets are:

Identified Intangible Asset		Estimated Useful Life in Years or Months
Developed technology		10 years- 20 years
Tradename		10 years
Customer relationships		10 years- 12.5 years
Backlog		1 month- 3 months
Non-compete agreement		15 months

Amortization of definite-lived intangible assets will be approximately (in thousands): $7,479 in fiscal year 2012, $6,381 in fiscal year 2013, $8,412 in fiscal year 2014, $10,745 in fiscal year 2015 and $13,209 in fiscal year 2016.

The roll forward of the goodwill balance by segment during the three months ended March 31, 2012 is as follows (in thousands):

	ACO			Thermo		ESK		Boron			Total
Balance at December 31, 2011
Goodwill	$	13,108		$	10,331	$	9,033	$	22,083		$	54,555
Accumulated impairment losses		(7,797	)		-		-		(3,832	)		(11,629	)
		5,311			10,331		9,033		18,251			42,926

Translation and other		-			-		265		-			265
Balance at March 31, 2012
Goodwill	$	13,108			10,331	$	9,298		22,083			54,820
Accumulated impairment losses		(7,797	)		-		-		(3,832	)		(11,629	)
		5,311		$	10,331		9,298	$	18,251		$	43,191

The Company is required to test annually whether the estimated fair value of its reporting units is sufficient to support the goodwill assigned to those reporting units; the Company performs the annual test in the fourth quarter. The Company is also required to test goodwill for impairment before the annual test if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying amount, such as a significant adverse change in the business climate. The Company determined that a test of goodwill for impairment was not required as of March 31, 2012.