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

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Revenue from External Customer [Line Items]

Net sales from product groups

$ 204,394

$ 166,453

$ 156,928

$ 141,645

$ 133,796

$ 141,447

$ 177,397

$ 190,868

$ 669,420

$ 643,508

$ 822,517

Instruments and Control Products [Member]

Revenue from External Customer [Line Items]

Net sales from product groups

266,838

258,521

348,735

Power and Reactive Gas Products [Member]

Revenue from External Customer [Line Items]

Net sales from product groups

273,357

251,669

327,151

Vacuum Products [Member]

Revenue from External Customer [Line Items]

Net sales from product groups

74,537

66,418

81,782

Analytical Solutions Group Products [Member]

Revenue from External Customer [Line Items]

Net sales from product groups

$ 54,688

$ 66,900

$ 64,849