Summary of significant accounting policies - Recently adopted accounting pronouncements (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 01, 2018	Jun. 29, 2019	Jun. 30, 2018	Jul. 01, 2017	Sep. 29, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings		$ 2,767,469	$ 3,235,894
Other assets		215,801	262,552
Selling, general and administrative expenses		1,874,651	1,991,401	$ 1,788,330
Other income (expense), net		$ 11,231	28,606	(33,717)
ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect on retained earnings	$ 2,000
ASU 2017-07
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Selling, general and administrative expenses			(21,300)	(17,700)
Other income (expense), net			$ 21,300	$ 17,700
ASU 2016-16
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings					$ (5,800)
Other assets					$ (5,800)