Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Dec. 29, 2012
Earn Out Liability
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Liabilities, Fair Value Measurements	$ 546	$ 652
Level 1 | Earn Out Liability
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Liabilities, Fair Value Measurements		0
Level 2 | Earn Out Liability
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Liabilities, Fair Value Measurements		0
Level 3 | Earn Out Liability
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Liabilities, Fair Value Measurements	546	652
Money market funds
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Assets, Fair Value Measurements	12,741	10,839
Money market funds | Level 1
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Assets, Fair Value Measurements	12,741	10,839
Money market funds | Level 2
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Assets, Fair Value Measurements		0
Money market funds | Level 3
Financial assets and liabilities measured and recognized at fair value on a recurring basis
Assets, Fair Value Measurements		$ 0