(Effective tax rate reconciliation) (Details)	12 Months Ended
	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Income Tax Disclosure [Abstract]
U.S. Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	1.00%	1.20%	0.90%
Foreign operations	(9.20%)	(6.20%)	(7.60%)
R&D tax credits	(0.60%)	(1.10%)	0.00%
Uncertain tax position adjustments	(1.60%)	(1.90%)	2.80%
Deferred tax adjustments, rate and other	(3.90%)	0.00%	(4.70%)
Valuation allowance on state deferred tax	(0.30%)	(0.80%)	0.80%
Other items	0.60%	(0.30%)	0.60%
Effective tax rate	21.00%	25.90%	27.80%