Commitments and Contingencies (Details) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jul. 01, 2015 |
Dec. 31, 2013 |
|
| Retail site | ||
| Loss Contingencies [Line Items] | ||
| Letters of credit outstanding | $ 160 | |
| Office building | ||
| Loss Contingencies [Line Items] | ||
| Letters of credit outstanding | $ 80 | |
| Letter of credit | ||
| Loss Contingencies [Line Items] | ||
| Renewal term | 1 year |