Fair Value of Financial Instruments (Details 5) (Assets and liabilities measured at fair value on recurring basis, Contingent consideration, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012
Assets and liabilities measured at fair value on recurring basis | Contingent consideration
Fair value liabilities reconciliation of changes
Balance at the beginning of the period	$ 2,750	$ 876
Issues	13,964	4,004
Gain recognized in earnings	(3,795)	(2,130)
Balance at the end of the period	12,919	2,750
Net gain for the period included in earnings attributable to contingent consideration held at the end of the period:	$ 1,045	$ 1,254