Acquisitions - Summary of Supplemental Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Professional Power Products, Inc. [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net sales		$ 353,175	$ 278,117
Net (loss) income		$ 23,671	$ (16,557)
(Loss) earnings per share, basic		$ 2.21	$ (1.69)
(Loss) earnings per share, diluted		$ 1.57	$ (1.69)
Powertrain Integration, LLC [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net sales	$ 402,718	$ 400,585
Net (loss) income	$ 14,868	$ 26,320
(Loss) earnings per share, basic	$ 1.38	$ 2.46
(Loss) earnings per share, diluted	$ 0.50	$ 1.81