The Company and Subsequent Event - Additional Information (Detail) In Thousands, except Share data, unless otherwise specified	1 Months Ended		9 Months Ended
	Feb. 22, 2013 USD ($)	Feb. 22, 2013 EUR (€)	Sep. 30, 2013 W.E.T. Bank of America credit facility USD ($)	Sep. 30, 2013 W.E.T. Bank of America credit facility EUR (€)	Oct. 31, 2013 W.E.T. Bank of America credit facility Subsequent Event EUR (€)	Sep. 30, 2013 W.E.T. Bank of America credit facility Minimum	Sep. 30, 2013 WET Historical Gentherm	Feb. 22, 2013 WET Historical Gentherm
Nature Of Company [Line Items]
Business Acquisition, shares acquired							309,537	442,253
Business Acquisition, percentage of shares acquired								14.00%
Business Acquisition, shares issued for acquisition	3,300,000	3,300,000
Business Acquisition, cash paid	$ 7,247	€ 5,408	$ 26,311	€ 35,256
Business Acquisition, percentage of shares acquired					100.00%	99.00%
Business Acquisition, purchase price per share				€ 85	€ 90.05
Business Acquisition cost of acquisition, financed by borrowings			$ 40,441