CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Oct. 02, 2016		Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 297,937		$ 264,705
Marketable securities	598,501		477,696
Accounts receivable, less allowance for doubtful accounts of $2,372 and $2,407 at October 2, 2016 and December 31, 2015, respectively	163,213		211,293
Inventories, net:
Parts	59,498		73,117
Assemblies in process	22,517		32,825
Finished goods	33,051		47,646
Inventory, Net, Total	115,066		153,588
Deferred tax assets			54,973
Prepayments	104,078		91,519
Other current assets	6,393		6,194
Total current assets	1,285,188		1,259,968
Property, plant and equipment, net	261,821		273,414
Marketable securities	357,751		265,928
Deferred tax assets	90,546		7,404
Other assets	12,777		13,080
Retirement plans assets	4,869		636
Intangible assets, net	114,146		239,831
Goodwill	238,589		488,413
Total assets	2,365,687	[1]	2,548,674
Current liabilities:
Accounts payable	61,890		92,358
Accrued employees' compensation and withholdings	89,723		113,994
Deferred revenue and customer advances	138,916		85,527
Other accrued liabilities	56,580		43,727
Contingent consideration	1,050		15,500
Accrued income taxes	20,925		21,751
Total current liabilities	369,084		372,857
Long-term deferred revenue and customer advances	26,336		25,745
Retirement plans liabilities	108,095		103,531
Deferred tax liabilities	16,837		26,663
Long-term other accrued liabilities	31,354		32,156
Long-term contingent consideration	31,837		21,936
Total liabilities	583,543		582,888
Commitments and contingencies (See Note P)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized; 201,643 and 203,641 shares issued and outstanding at October 2, 2016 and December 31, 2015, respectively	25,205		25,455
Additional paid-in capital	1,517,957		1,480,647
Accumulated other comprehensive income (loss)	3,385		(8,144)
Retained earnings	235,597		467,828
Total shareholders' equity	1,782,144		1,965,786
Total liabilities and shareholders' equity	$ 2,365,687		$ 2,548,674

[1] Total business assets are directly attributable to each business. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.