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Associate Retirement Plans - Summary of Reconciliation of Beginning and Ending Balances for Level 3 Assets (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 30, 2017 | Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items] |  |
Balance at beginning of year | $ 81,982 |
Balance at end of year | 81,255 | $ 81,982
Guaranteed annuity contract [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Balance at beginning of year | 15,426 |
Balance at end of year | 13,891 | 15,426
Significant unobservable inputs (Level 3) [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Balance at beginning of year | 15,426 |
Balance at end of year | 13,891 | 15,426
Significant unobservable inputs (Level 3) [Member] | Guaranteed annuity contract [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Balance at beginning of year | 15,426 | 16,198
Purchases, sales, issuances and settlements, net | (2,222) | (1,733)
Interest income | 552 | 631
Unrealized gains | 135 | 330
Balance at end of year | $ 13,891 | $ 15,426

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- Definition Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from actual return (loss) on assets sold. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(02)(A) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from purchases, sales and settlements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(02)(B) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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