Segments, Concentrations and Geographic Information - Reconciliation of Segment Assets to Consolidated Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization	$ 30.7	$ 32.1
Total assets	4,167.5	4,216.2	$ 4,208.1
Corporate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization	0.7	0.6
Total assets	140.7	240.6
Power Transmission Technologies [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization	8.0	8.2
Total assets	1,059.9	1,047.4
Automation & Specialty [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization	22.0	23.3
Total assets	$ 2,966.9	$ 2,928.2