(Effective tax rate reconciliation) (Details)	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
U.S. Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	1.20%	0.90%	0.80%
Foreign operations	(6.20%)	(7.60%)	(8.50%)
R&D tax credits	(1.10%)	0.00%	(0.50%)
Uncertain tax position adjustments	(1.90%)	2.80%	(0.30%)
State deferred tax rate adjustments	0.00%	(4.70%)	0.00%
Valuation allowance on state deferred tax	(0.80%)	0.80%	(0.10%)
Other items	(0.30%)	0.60%	0.50%
Effective tax rate	25.90%	27.80%	26.90%