Components of Net Periodic Pension Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 379	$ 335	$ 355
Interest cost	80	78	53
Amortization of actuarial loss (gains)	27		37
Net periodic benefit cost	486	413	445
Gentherm GmbH
Defined Benefit Plan Disclosure [Line Items]
Service cost		304
Interest cost	142	181	180
Return on plan assets	(126)	(89)	(59)
Amortization of prior service cost	572
Amortization of actuarial loss (gains)	59	(166)	(37)
Net periodic benefit cost	$ 647	$ 230	$ 84