Fair Value of Plan Assets (Detail) - Gentherm GmbH - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Change in plan assets:
Plan assets at beginning of year	$ 3,333	$ 3,615
Actual return on plan assets	125	126
Contributions	261	257
Paid pension distributions	(261)	(257)
Actuarial gains/(losses)	(27)	(28)
Exchange rate impact	(105)	(380)
Plan assets at end of year	$ 3,326	$ 3,333