Income taxes (Tax Cuts and Jobs Act of 2017) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Dec. 29, 2018	Sep. 29, 2018	Dec. 30, 2017	Dec. 29, 2018	Dec. 30, 2017
Income taxes
Transition tax	$ 257.5			$ 257.5
Transition tax increase to provisional estimate	10.8
Deferred taxes change in tax rate adjustment	$ (1.3)	$ (2.4)
Effective tax rate	43.30%		8.60%	33.10%	7.00%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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