Taxes (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Oct. 02, 2011	Oct. 03, 2010	Oct. 02, 2011	Oct. 03, 2010	Dec. 31, 2010
Taxes (Textual) [Abstract]
Provision for effective tax rate	21.00%	20.00%	22.00%	22.00%
Decrease in tax expense of due to the settlement of the competent Authority tax case with Japan	$ 155,000	$ 462,000
Decrease in tax expense for the final true-up of the prior year's tax accrual upon filing the actual tax returns	574,000	151,000
Decrease in tax expense upon the expiration of the statutes of limitation for certain reserves for income tax uncertainties	808,000	105,000
Valuation allowance related to foreign tax credits	2,457,000
Effective discrete tax rate	23.00%	23.00%	23.00%	23.00%
Increase in liabilities, net of deferred tax benefit.	179,000		478,000
Estimated interest and penalties	20,000		61,000
Interest and penalties, gross	1,158,000		1,158,000
Reserve for income taxes, current	558,000		558,000
Reserve for income taxes	4,291,000		4,291,000		5,361,000
Reserve for income taxes, total	4,849,000		4,849,000
Reserve for income taxes recorded in additional paid in capital	147,000		147,000
Release of reserves, lower range	250,000		250,000
Release of reserves, upper range	$ 500,000		$ 500,000
Tax years open to examination by various taxing authorities			2007 through 2010