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
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Operating Statistics [Line Items]
Capital expenditures	$ 3,356	$ 4,567
Depreciation and amortization	4,092	3,143
Accounts receivable	90,457		82,060
Inventory	131,253		134,639
Total segment assets	221,710		216,699
Advanced Manufacturing Capital Equipment [Member]
Operating Statistics [Line Items]
Capital expenditures	2,612	3,176
Depreciation and amortization	2,941	2,138
Accounts receivable	13,696		9,644
Inventory	106,872		108,397
Total segment assets	120,568		118,041
Analytical Solutions Group [Member]
Operating Statistics [Line Items]
Capital expenditures	111	115
Depreciation and amortization	243	199
Accounts receivable	5,497		5,889
Inventory	3,975		3,841
Total segment assets	9,472		9,730
Europe Region Sales & Service Operations [Member]
Operating Statistics [Line Items]
Capital expenditures	15	45
Depreciation and amortization	74	81
Accounts receivable	5,865		5,813
Inventory	3,770		3,691
Total segment assets	9,635		9,504
Asia Region Sales & Service Operations [Member]
Operating Statistics [Line Items]
Capital expenditures	63	292
Depreciation and amortization	294	369
Accounts receivable	33,413		32,088
Inventory	24,367		29,534
Total segment assets	57,780		61,622
Corporate, Eliminations and Other [Member]
Operating Statistics [Line Items]
Capital expenditures	555	939
Depreciation and amortization	540	356
Accounts receivable	31,986		28,626
Inventory	(7,731)		(10,824)
Total segment assets	$ 24,255		$ 17,802