Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Apr. 01, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 533,396	$ 573,736
Marketable securities	87,223	96,502
Accounts receivable, less allowance for doubtful accounts of $4,102 at April 1, 2012 and December 31, 2011	221,547	129,330
Inventories:
Parts	89,125	109,315
Assemblies in process	28,576	33,856
Finished goods	20,529	16,892
Inventories, total	138,230	160,063
Deferred tax assets	56,601	53,948
Prepayments and other current assets	83,994	86,308
Total current assets	1,120,991	1,099,887
Property, plant and equipment	809,249	798,194
Less: Accumulated depreciation	570,632	565,987
Net property, plant and equipment	238,617	232,207
Long-term marketable securities	121,512	84,407
Retirement plan assets	9,244	8,840
Intangible assets, net	374,546	392,975
Goodwill	352,778	352,778
Other assets	20,460	17,545
Total assets	2,238,148	2,188,639
Current liabilities:
Accounts payable	106,381	69,842
Accrued employees' compensation and withholdings	59,321	90,427
Deferred revenue and customer advances	86,622	78,670
Contingent consideration	61,210	68,892
Other accrued liabilities	59,857	63,280
Current debt	2,431	2,573
Total current liabilities	375,822	373,684
Long-term deferred revenue and customer advances	23,885	33,541
Retirement plan liabilities	78,251	76,638
Deferred tax liabilities	29,395	16,049
Long-term other accrued liabilities	20,299	23,711
Long-term debt	161,803	159,956
Total liabilities	689,455	683,579
Commitments and contingencies (Note O)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized, 186,418 shares and 183,587 shares issued and outstanding at April 1, 2012 and December 31, 2011, respectively	23,302	22,948
Additional paid-in capital	1,302,660	1,293,130
Accumulated other comprehensive income	4,933	4,746
Retained earnings	217,798	184,236
Total shareholders' equity	1,548,693	1,505,060
Total liabilities and shareholders' equity	$ 2,238,148	$ 2,188,639