Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2018	Jul. 01, 2017	Jul. 02, 2016	Jun. 29, 2019
Components of net periodic pension costs
Service cost	$ 15,834	$ 29,623	$ 39,740
Interest cost	23,732	19,323	21,310
Expected return on plan assets	(54,686)	(49,279)	(40,285)
Amortization of prior service credits	(1,573)	(1,573)	(1,573)
Recognized net actuarial loss	14,404	14,440	12,731
Curtailment recognition of prior service credit		(614)
Pension settlement charge	22,365
Net periodic pension cost	20,076	11,920	$ 31,923
Contributions	$ 16,000	$ 33,750
Forecast
Components of net periodic pension costs
Estimated future employer pension plan contributions				$ 16,000

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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- Definition

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

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- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ 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)(ii)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 6
-Subparagraph (b)
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-Publisher FASB
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-Section 50
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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-Section 50
-Paragraph 1
-Subparagraph (d)(5)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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Amount of contributions expected to be received by defined benefit plan from employer in fiscal year. Excludes contributions paid by employer in current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920

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- Definition

Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from event reducing expected years of future service of present employees or eliminating accrual of defined benefits for some or all future services of present employees.

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- Definition

Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of (increase) decrease to benefit obligation of defined benefit plan from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Includes, but is not limited to, lump-sum cash payment to participant in exchange for right to receive specified benefits, purchase of nonparticipating annuity contract and change from remeasurement.

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