Restructuring charges and impairment charges - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017	May 01, 2018
2018 Footprint realignment plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs expected cash payment	$ 1.0		$ 1.0
Restructuring reserve	51.4		51.4
2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges					$ 102.0
2018 Footprint realignment plan | Minimum | Accelerated Depreciation And Other Costs
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges					40.0
2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges					133.0
2018 Footprint realignment plan | Maximum | Accelerated Depreciation And Other Costs
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges					$ 59.0
2016 Footprint realignment plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	43.0		43.0
Aggregate restructuring charges incurred	17.1		17.1
Restructuring reserve	6.3		6.3
2016 Footprint realignment plan | Accelerated Depreciation And Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	2.0	$ 2.0	3.3	$ 4.1
Aggregate restructuring charges incurred	18.0		18.0
2014 Footprint realignment plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	27.9
Aggregate restructuring charges incurred	12.2		12.2
Restructuring reserve	3.9		3.9
2014 Footprint realignment plan | Accelerated Depreciation And Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	0.6	$ 0.5	1.0	$ 2.1
2014 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	46.0		46.0
2014 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 51.0		$ 51.0