Business Segment, Geographic Area, Product and Significant Customer Information - Schedule of Capital Expenditures, Depreciation and Amortization Expense and Segment Assets by Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Capital expenditures	$ 2,107	$ 2,794	$ 9,362	$ 9,154
Depreciation and amortization	5,792	4,245	14,757	12,715
Accounts receivable	106,290		106,290		116,744
Inventory	153,930		153,930		142,727
Total segment assets	260,220		260,220		259,471
Operating Segments [Member] | Advanced Manufacturing Capital Equipment [Member]
Segment Reporting Information [Line Items]
Capital expenditures	1,341	1,893	5,282	6,599
Depreciation and amortization	4,393	2,861	10,816	8,819
Accounts receivable	15,853		15,853		20,767
Inventory	125,309		125,309		117,822
Total segment assets	141,162		141,162		138,589
Operating Segments [Member] | Analytical Solutions Group [Member]
Segment Reporting Information [Line Items]
Capital expenditures	21	125	1,823	265
Depreciation and amortization	319	319	795	923
Accounts receivable	4,843		4,843		5,603
Inventory	4,638		4,638		4,391
Total segment assets	9,481		9,481		9,994
Operating Segments [Member] | Europe Region Sales & Service Operations [Member]
Segment Reporting Information [Line Items]
Capital expenditures	60	24	87	137
Depreciation and amortization	85	86	260	260
Accounts receivable	7,711		7,711		6,538
Inventory	3,697		3,697		4,254
Total segment assets	11,408		11,408		10,792
Operating Segments [Member] | Asia Region Sales & Service Operations [Member]
Segment Reporting Information [Line Items]
Capital expenditures	307	239	560	435
Depreciation and amortization	295	294	874	876
Accounts receivable	36,800		36,800		44,207
Inventory	27,612		27,612		25,094
Total segment assets	64,412		64,412		69,301
Corporate, Eliminations and Other [Member]
Segment Reporting Information [Line Items]
Capital expenditures	378	513	1,610	1,718
Depreciation and amortization	700	685	2,012	1,837
Accounts receivable	41,083		41,083		39,629
Inventory	(7,326)		(7,326)		(8,834)
Total segment assets	$ 33,757		$ 33,757		$ 30,795