Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 42,463	$ 40,644
Short-term investments	41,777	184,822
Accounts receivable, less reserves of $1,328 and $1,354 in 2014 and 2013, respectively	51,947	53,015
Inventories	28,434	25,694
Deferred income taxes	7,463	7,611
Prepaid expenses and other current assets	17,797	20,265
Total current assets	189,881	332,051
Long-term investments	379,916	229,655
Property, plant, and equipment, net	37,826	37,136
Deferred income taxes	12,288	12,307
Intangible assets, net	13,807	14,723
Goodwill	81,689	81,689
Other assets	2,110	2,138
Total assets	717,517	709,699
Current liabilities:
Accounts payable	9,671	9,487
Accrued expenses	26,140	34,331
Accrued income taxes	276	1,263
Deferred revenue and customer deposits	16,443	15,941
Total current liabilities	52,530	61,022
Reserve for income taxes	3,939	4,765
Commitments and contingencies (Note 7)
Shareholders' equity:
Common stock, $.002 par value – Authorized: 140,000 shares, issued and outstanding: 86,840 and 86,831 shares in 2014 and 2013, respectively	174	174
Additional paid-in capital	223,560	211,440
Retained earnings	466,350	462,131
Accumulated other comprehensive loss, net of tax	(29,036)	(29,833)
Total shareholders’ equity	661,048	643,912
Total liabilities and shareholders' equity	$ 717,517	$ 709,699