Revenue Recognition - Disaggregates Revenue for Each Reportable Segment and Geographic Region (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Net sales	$ 400.8	$ 466.5	$ 835.0	$ 949.3
North America (primarily U.S.) [Member]
Disaggregation Of Revenue [Line Items]
Net sales	205.8	269.8	451.1	542.8
Europe Excluding Germany [Member]
Disaggregation Of Revenue [Line Items]
Net sales	71.3	79.9	146.1	161.7
Germany [Member]
Disaggregation Of Revenue [Line Items]
Net sales	44.1	56.8	96.6	119.0
Asia And Other [Member]
Disaggregation Of Revenue [Line Items]
Net sales	79.6	60.0	141.2	125.8
Operating Segments [Member] | Power Transmission Technologies [Member]
Disaggregation Of Revenue [Line Items]
Net sales	196.3	234.9	413.0	469.8
Operating Segments [Member] | Automation & Specialty [Member]
Disaggregation Of Revenue [Line Items]
Net sales	205.8	233.3	424.4	482.4
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ (1.3)	$ (1.7)	$ (2.4)	$ (2.9)