Goodwill and intangible assets Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 27, 2020	Jan. 02, 2021
Finite-Lived Intangible Assets [Line Items]
Acquired amount	$ 406,276	$ 440,932
Accumulated Amortization	(340,839)	(402,120)
Net Book Value	65,437	38,812
Intangible asset impairment	17,473
Customer related
Finite-Lived Intangible Assets [Line Items]
Acquired amount	300,937	325,799
Accumulated Amortization	(266,759)	(312,345)
Net Book Value	34,178	13,454
Trade name
Finite-Lived Intangible Assets [Line Items]
Acquired amount	51,698	56,716
Accumulated Amortization	(32,493)	(40,161)
Net Book Value	19,205	16,555
Technology and other
Finite-Lived Intangible Assets [Line Items]
Acquired amount	53,641	58,417
Accumulated Amortization	(41,587)	(49,614)
Net Book Value	$ 12,054	$ 8,803