Segments, Concentrations and Geographic Information - Reconciliation of Segment Assets to Consolidated Assets (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		$ 32.1	$ 9.4	$ 96.4	$ 28.0
Total assets		4,293.7	912.6	4,293.7	912.6	$ 4,337.2
Corporate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		0.6	0.8	2.0	2.6
Total assets	[1]	143.4	29.7	143.4	29.7
Power Transmission Technologies [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		8.3	8.6	25.0	25.4
Total assets		1,064.7	$ 882.9	1,064.7	$ 882.9
Automation & Specialty [Member] | Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total depreciation and amortization		23.2		69.4
Total assets		$ 3,085.6		$ 3,085.6

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