Supplemental Balance Sheet Information (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Inventories
Raw materials and purchased parts	$ 65,117	$ 65,054
Work in process	18,619	19,257
Finished goods	24,982	28,657
Inventories	$ 108,718	$ 112,968

Amount before last-in first-out (LIFO) and valuation reserves of merchandise or goods held by the entity that are readily available for sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

-Number 210

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- Definition

Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Topic 210

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Topic 330

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- Definition

Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Gross amount of merchandise or goods which are partially completed, are generally comprised of raw materials, labor and factory overhead costs, and which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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