Pension and retirement plans (Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jul. 01, 2017	Jul. 02, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 659,038	$ 699,365	$ 516,089
Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	659,038	699,365
Recurring | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,291	1,481
Recurring | U.S. common stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	262,066	221,003
Recurring | International common stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	133,564	117,392
Recurring | U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,414	105,227
Recurring | International government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		14,366
Recurring | U.S. corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		214,024
Recurring | U.S. and international corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	133,645
Recurring | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26,058	25,872
Level 1 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,291	1,481
Level 1 | Recurring | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,291	1,481
Level 2 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	651,747	697,884
Level 2 | Recurring | U.S. common stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	262,066	221,003
Level 2 | Recurring | International common stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	133,564	117,392
Level 2 | Recurring | U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,414	105,227
Level 2 | Recurring | International government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		14,366
Level 2 | Recurring | U.S. corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		214,024
Level 2 | Recurring | U.S. and international corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	133,645
Level 2 | Recurring | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 26,058	$ 25,872