Segment information - Sales and Adjusted EBITDA by Reporting Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Segment Reporting Information
Net sales	$ 712.2	$ 746.6	$ 1,998.8	$ 2,361.4
Adjusted EBITDA	140.0	145.0	344.0	475.9
Power Transmission
Segment Reporting Information
Net sales	469.2	474.4	1,280.4	1,475.4
Adjusted EBITDA	99.3	99.7	236.5	315.2
Fluid Power
Segment Reporting Information
Net sales	243.0	272.2	718.4	886.0
Adjusted EBITDA	$ 40.7	$ 45.3	$ 107.5	$ 160.7