(Effective tax rate reconciliation) (Details)	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Income Tax Disclosure [Abstract]
U.S. Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	0.90%	0.80%	0.50%
Foreign operations	(7.60%)	(8.50%)	(5.90%)
R&D tax credits	0.00%	(0.50%)	(0.80%)
Uncertain tax position adjustments	2.80%	(0.30%)	(5.40%)
State deferred tax rate adjustments	(4.70%)	0.00%	(2.90%)
Valuation allowance on state deferred tax	0.80%	(0.10%)	6.10%
Other items	0.60%	0.50%	0.80%
Effective tax rate	27.80%	26.90%	27.40%