Segments, Concentrations and Geographic Information - Segment Financial Information and Reconciliation of Segments Revenue to Unaudited Condensed Consolidated Revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 472.1	$ 434.2
Income/(loss) from operations	65.1	(98.0)
Restructuring costs	(0.9)	(1.6)
Net interest expense	16.9	17.4
Other non-operating expense, net	(1.5)	(1.5)
Total other non-operating (income) expense, net	15.4	15.9
Income/(Loss) before income taxes	49.7	(113.9)
Provision for income taxes	10.5	2.7
Net income/(loss)	39.2	(116.6)
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Restructuring costs	(0.9)	(1.6)
Operating Segments [Member] | Power Transmission Technologies [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	221.0	216.7
Income/(loss) from operations	27.8	25.7
Restructuring costs	(0.6)	(0.6)
Operating Segments [Member] | Automation & Specialty [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	252.1	218.6
Income/(loss) from operations	41.4	(118.7)
Restructuring costs	(0.3)	(1.0)
Intersegment Eliminations [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	(1.0)	(1.1)
Corporate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Income/(loss) from operations	$ (3.2)	$ (3.4)