Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials and assembled parts	$ 55,373	$ 61,644
Service inventories, estimated current requirements	11,992	12,398
Work-in-process	77,171	76,402
Finished goods	18,966	25,996
Total current inventories	163,502us-gaap_InventoryNet	176,440us-gaap_InventoryNet
Non-current inventories	$ 49,019us-gaap_InventoryNoncurrent	$ 50,731us-gaap_InventoryNoncurrent

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Inventories not expected to be converted to cash, sold or exchanged within the normal operating cycle.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process.

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Carrying amount, net of reserves and adjustments, as of the balance sheet date of merchandise or goods which are partially completed. This inventory is generally comprised of raw materials, labor and factory overhead costs, 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.

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