Segments, Concentrations and Geographic Information - Reconciliation of Segment Assets to Consolidated Assets (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		$ 32.1	$ 9.4
Total assets		4,380.3	938.5	$ 4,337.2
Corporate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		0.7	0.9
Total assets	[1]	97.7	29.6
Power Transmission Technologies [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		8.4	8.5
Total assets		1,091.4	$ 908.9
Automation & Specialty [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		23.0
Total assets		$ 3,191.2

[1] Corporate assets are primarily cash and cash equivalents, tax related asset accounts, certain capitalized software costs, and property, plant and equipment.