Pension and retirement plans (Fair Value) (Details) - USD ($) $ in Thousands	Jul. 03, 2021	Jun. 27, 2020	Jun. 29, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 772,279	$ 707,800	$ 664,063
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,655	13,243
Common Stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	290,347	254,917
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	124,363	81,817
High yield credit and bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	117,722	103,925
U.S. government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	186,279	218,573
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36,913	35,325
Level 1 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,655	13,243
Level 1 | Recurring | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,655	13,243
Net Asset Value | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	755,624	694,557
Net Asset Value | Recurring | Common Stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	290,347	254,917
Net Asset Value | Recurring | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	124,363	81,817
Net Asset Value | Recurring | High yield credit and bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	117,722	103,925
Net Asset Value | Recurring | U.S. government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	186,279	218,573
Net Asset Value | Recurring | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 36,913	$ 35,325