Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013		Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 30,446		$ 45,160
Short-term investments	186,572		105,105
Accounts receivable, less reserves of $1,346 and $1,131 in 2013 and 2012, respectively	48,832		42,387
Inventories	27,625		26,182
Deferred income taxes	6,292		6,369
Prepaid expenses and other current assets	19,300		14,394
Total current assets	319,067		239,597
Long-term investments	226,720		238,255
Property, plant, and equipment, net	35,565		34,820
Deferred income taxes	15,503		15,647
Intangible assets, net	11,890		14,770
Goodwill	81,689		81,689
Other assets	2,316		2,827
Total assets	692,750		627,605
Current liabilities:
Accounts payable	7,457		6,815
Accrued expenses	31,367		29,590
Accrued income taxes	90		1,009
Deferred revenue and customer deposits	11,722		12,690
Total current liabilities	50,636		50,104
Reserve for income taxes	4,390		5,216
Commitments and contingencies (Note 8)
Shareholders' equity:
Common stock, $.002 par value - Authorized: 140,000 shares, issued: 87,281 and 86,110 shares in 2013 and 2012, respectively	175	[1]	172	[1]
Additional paid-in capital	206,152	[1]	165,162	[1]
Retained earnings	461,538	[1]	436,466	[1]
Accumulated other comprehensive loss, net of tax	(30,141)	[1]	(29,515)	[1]
Total shareholders' equity	637,724	[1]	572,285	[1]
Total liabilities and shareholders' equity	$ 692,750		$ 627,605

[1] Prior period amounts have been adjusted to reflect the two-for-one stock split effected in the form of a stock dividend which occurred in September 2013.