Revenue Recognition - Disaggregates Revenue for Each Reportable Segment and Geographic Region (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation Of Revenue [Line Items]
Net sales	$ 434.2	$ 482.8
North America (primarily U.S.) [Member]
Disaggregation Of Revenue [Line Items]
Net sales	245.3	273.0
Europe Excluding Germany [Member]
Disaggregation Of Revenue [Line Items]
Net sales	74.8	81.7
Germany [Member]
Disaggregation Of Revenue [Line Items]
Net sales	52.5	62.2
Asia And Other [Member]
Disaggregation Of Revenue [Line Items]
Net sales	61.6	65.9
Operating Segments [Member] | Power Transmission Technologies [Member]
Disaggregation Of Revenue [Line Items]
Net sales	216.7	234.9
Operating Segments [Member] | Automation & Specialty [Member]
Disaggregation Of Revenue [Line Items]
Net sales	218.6	249.1
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ (1.1)	$ (1.2)