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Cash, Cash Equivalents, and Investments (Detail) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jul. 03, 2016 | Jul. 05, 2015 | Jul. 03, 2016 | Jul. 05, 2015
Cash and Cash Equivalents [Abstract] |  |  |  |
Gross realized gains on sale of investments | $ 141,000 | $ 210,000 | $ 225,000 | $ 408,000
Gross realized losses on sale of investments | 0 | $ 18,000 | 97,000 | $ 187,000
Maximum amount committed to invest in limited partnership |  |  | 20,500,000 |
Contribution to limited partnership | 19,886,000 |  | $ 19,886,000 |
Investment expiration date |  |  | Dec. 31, 2017 |
Remaining amount of commitment in limited partnership | $ 614,000 |  | $ 614,000 |
Contributions made during the period |  |  | 0 |
Distributions received during the period |  |  | $ 0 |

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