Business Segment, Geographic Area, Product and Significant Customer Information - Worldwide Net Revenue for Each Group of Products (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenue from External Customer [Line Items]
Net sales from product groups	$ 141,645	$ 190,868
Instruments and Control Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	60,028	77,481
Power and Reactive Gas Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	52,063	77,566
Vacuum Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	15,158	20,028
Analytical Solutions Group Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	$ 14,396	$ 15,793