Restructuring, Asset Impairment, and Transition Expenses - Summary of Total Restructuring Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,198	$ 1,641	$ 3,096	$ 3,194
Operating Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,198	1,641	3,096	3,194
Operating Segments [Member] | Couplings, Clutches and Brakes [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	488	1,089	1,849	1,493
Operating Segments [Member] | Electromagnetic Clutches and Brakes [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs		345		1,017
Operating Segments [Member] | Gearing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	488		784	16
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 222	$ 207	$ 463	$ 668