Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	May. 19, 2015	May. 01, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Private placement warrant income		$ 8,750,000	$ 858,000	$ 8,040,000	$ 1,190,000
Contingent consideration liability								$ 8,900,000
Change in the fair value of contingent consideration			$ 3,208,000	$ 50,000	$ 3,782,000
Professional Power Products, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability description				a ten percentage point change in the volatility factor would result in an immaterial increase or decrease in the fair value of the contingent consideration.
Decrease in volatility factor				10.00%
Contingent consideration liability		8,150,000		$ 8,150,000
Bi-Phase Technologies, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability		540,000		$ 540,000			$ 540,000
Bi-Phase Technologies, LLC [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, earn-out period				3 years
Bi-Phase Technologies, LLC [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, earn-out period				5 years
Powertrain Integration, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability		8,200,000		$ 8,200,000		$ 8,200,000
Change in contingent liability	$ 50,000			50,000
Change in the fair value of contingent consideration		$ 50,000		$ 50,000
Private Placement Warrants [Member] | Black-Scholes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated price volatility percentage		10.00%		10.00%