| Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended | |
|---|---|---|
| Dec. 29, 2012 | Dec. 31, 2011 | |
| Financial assets valued on recurring basis | ||
| Assets, fair value | $ 1,140 | $ 13,564 | 
| Level 1 [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 1,140 | 11,460 | 
| Level 2 [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Level 3 [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 2,104 | |
| Valuation Techniques a [Member] | Cash and cash equivalents [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 1,030 | 10,335 | 
| Valuation Techniques | (a) | (a) | 
| Valuation Techniques a [Member] | Investments - mutual funds [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 110 | 1,125 | 
| Valuation Techniques | (a) | (a) | 
| Valuation Techniques a [Member] | Level 1 [Member] | Cash and cash equivalents [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 1,030 | 10,335 | 
| Valuation Techniques a [Member] | Level 1 [Member] | Investments - mutual funds [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 110 | 1,125 | 
| Valuation Techniques a [Member] | Level 2 [Member] | Cash and cash equivalents [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Valuation Techniques a [Member] | Level 2 [Member] | Investments - mutual funds [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Valuation Techniques a [Member] | Level 3 [Member] | Cash and cash equivalents [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Valuation Techniques a [Member] | Level 3 [Member] | Investments - mutual funds [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Valuation Techniques b [Member] | Investments - ARPS [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | 2,104 | |
| Valuation Techniques | (b) | |
| Valuation Techniques b [Member] | Level 2 [Member] | Investments - ARPS [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | ||
| Valuation Techniques b [Member] | Level 3 [Member] | Investments - ARPS [Member] | ||
| Financial assets valued on recurring basis | ||
| Assets, fair value | $ 2,104 | |