Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Product revenues	$ 856,445	$ 811,300	$ 662,082
Cost of sales	580,066	569,618	487,320
Gross margin	276,379	241,682	174,762
Operating costs and expenses:
Research and development expenses	69,211	66,411	52,197
Reimbursed research and development expenses	(9,607)	(8,885)	(2,324)
Net research and development expenses	59,604	57,526	49,873
Acquisition transaction expenses		1,075	2,414
Selling, general and administrative expenses	95,456	84,647	72,091
Total operating costs and expenses	155,060	143,248	124,378
Operating income	121,319	98,434	50,384
Interest expense	(2,610)	(3,262)	(3,543)
Debt retirement expense		(1,370)
Revaluation of derivatives (loss) gain	(1,102)	(518)	1,006
Gain on settlement of lawsuit	9,949
Foreign currency gain (loss)	1,121	(218)	(2,228)
Gain from equity investment		785	436
Other income	261	370	175
Earnings before income tax	128,938	94,221	46,230
Income tax expense	33,545	24,102	11,097
Net income	95,393	70,119	35,133
Income attributable to non-controlling interest			(1,313)
Net income attributable to Gentherm Incorporated	95,393	70,119	33,820
Convertible preferred stock dividends			(1,622)
Net income attributable to common shareholders	$ 95,393	$ 70,119	$ 32,198
Basic earnings per share	$ 2.65	$ 1.98	$ 0.96
Diluted earnings per share	$ 2.62	$ 1.95	$ 0.94
Weighted average number of shares—basic	36,031,792	35,411,608	33,652,646
Weighted average number of shares—diluted	36,475,102	36,049,331	34,123,641