FAIR VALUE - Asset Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Jun. 27, 2020
Money market funds | Cash and Cash Equivalents
Fair Value
Investments at fair value	$ 100
Money market funds | Restricted Investments
Fair Value
Investments at fair value	2,800
Fixed Income | Restricted Investments
Fair Value
Investments at fair value	18,200
Mutual funds, equity and alternative investments | Investments
Fair Value
Investments at fair value	33,700
Money market and mutual funds | Other Assets
Fair Value
Investments at fair value	700
Ardellis Insurance Ltd.
Fair Value
Total Fair Value	51,681	$ 35,650
Estimate of Fair Value Measurement | Recurring
Fair Value
Investments at fair value	55,506	39,708
Assets at fair value	55,506	39,708
Estimate of Fair Value Measurement | Recurring | Money market funds
Fair Value
Investments at fair value	2,859	3,141
Estimate of Fair Value Measurement | Recurring | Fixed Income
Fair Value
Investments at fair value	17,854	16,456
Estimate of Fair Value Measurement | Recurring | Treasury securities
Fair Value
Investments at fair value	307
Estimate of Fair Value Measurement | Recurring | Equity
Fair Value
Investments at fair value	19,014	9,958
Estimate of Fair Value Measurement | Recurring | Alternative Investments
Fair Value
Investments at fair value	3,304	1,836
Estimate of Fair Value Measurement | Recurring | Mutual Fund
Fair Value
Investments at fair value	12,168	8,317
Estimate of Fair Value Measurement | Recurring | Domestic stock
Fair Value
Investments at fair value	10,037	6,359
Estimate of Fair Value Measurement | Recurring | International stock funds
Fair Value
Investments at fair value	1,463	1,124
Estimate of Fair Value Measurement | Recurring | Target funds
Fair Value
Investments at fair value	22	270
Estimate of Fair Value Measurement | Recurring | Bond funds
Fair Value
Investments at fair value	145	232
Estimate of Fair Value Measurement | Recurring | Alternative funds
Fair Value
Investments at fair value	501	332
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1)
Fair Value
Investments at fair value	31,752	18,579
Assets at fair value	31,752	18,579
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Money market funds
Fair Value
Investments at fair value	19	57
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Fixed Income
Fair Value
Investments at fair value	244	247
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Treasury securities
Fair Value
Investments at fair value	307
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Equity
Fair Value
Investments at fair value	19,014	9,958
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Mutual Fund
Fair Value
Investments at fair value	12,168	8,317
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Domestic stock
Fair Value
Investments at fair value	10,037	6,359
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | International stock funds
Fair Value
Investments at fair value	1,463	1,124
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Target funds
Fair Value
Investments at fair value	22	270
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Bond funds
Fair Value
Investments at fair value	145	232
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Alternative funds
Fair Value
Investments at fair value	501	332
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2)
Fair Value
Investments at fair value	20,450	19,293
Assets at fair value	20,450	19,293
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2) | Money market funds
Fair Value
Investments at fair value	2,840	3,084
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2) | Fixed Income
Fair Value
Investments at fair value	17,610	16,209
Estimate of Fair Value Measurement | Recurring | Prices with Unobservable Inputs (Level 3)
Fair Value
Investments at fair value	3,304	1,836
Assets at fair value	3,304	1,836
Estimate of Fair Value Measurement | Recurring | Prices with Unobservable Inputs (Level 3) | Alternative Investments
Fair Value
Investments at fair value	$ 3,304	$ 1,836