Benefit Plans - Reconciliation of Plan Assets Fair Value (Detail) - USD ($) $ in Thousands	12 Months Ended
Jan. 01, 2017	Jan. 03, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 213,378
Fair value of plan assets at end of year	227,549	$ 213,378
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	2,377	2,156
Plan participants’ contributions	662	594
Benefits paid	(3,135)	(2,886)
Medicare Part D subsidy reimbursement	$ 96	$ 136

The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
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-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Amount of contributions made by the employer to defined benefit plans.

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The amount of contributions made by plan participants. This item represents a periodic increase to the plan obligation and an increase to plan assets.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

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Amount of the period's gross receipts received from the prescription drug subsidy, which is to be used in the roll forward of the accumulated postretirement benefit obligation of an applicable postretirement benefit plan.

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