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           Supplemental Retirement Plan and Related Post Retirement Benefits - Net Periodic Pension Cost or Net Periodic Cost Recognized for Defined Benefit Plans (Detail) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
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           Sep. 28, 2013 
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           Sep. 29, 2012 
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           Sep. 28, 2013 
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           Sep. 29, 2012 
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| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 74 | $ 88 | $ 222 | $ 215 | 
| Interest cost | 155 | 148 | 465 | 400 | 
| Amortization of prior service cost | 121 | 122 | 370 | 304 | 
| Amortization of net actuarial losses | 32 | 22 | 95 | 69 | 
| Net periodic cost | 382 | 380 | 1,152 | 988 | 
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           SERP [Member] 
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| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | 1 | 1 | 3 | 2 | 
| Interest cost | 6 | 6 | 18 | 18 | 
| Amortization of prior service cost | 6 | 6 | 18 | 19 | 
| Net periodic cost | $ 13 | $ 13 | $ 39 | $ 39 | 
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- Definition 
          The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
          
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- Definition 
          Amount included in accumulated other comprehensive income (AOCI) related to gain (loss) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position. No definition available. 
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- Definition 
          The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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