Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Product revenues	$ 662,082	$ 554,979	$ 369,588
Cost of sales	487,320	413,052	274,621
Gross margin	174,762	141,927	94,967
Operating costs and expenses:
Research and development expenses	52,197	43,189	30,665
Reimbursed research and development expenses	(2,324)	(2,239)	(932)
Net research and development expenses	49,873	40,950	29,733
Acquisition transaction expenses	2,414		5,316
Selling, general and administrative expenses	72,895	64,919	42,110
Total operating costs and expenses	125,182	105,869	77,159
Operating income	49,580	36,058	17,808
Interest (expense)	(3,543)	(4,136)	(3,511)
Debt retirement expense			(1,160)
Revaluation of derivatives	1,006	(2,292)	(6,118)
Foreign currency (loss) gain	(2,228)	2,201	9,207
Gain (loss) from equity investment	436	(82)	(243)
Other income (loss)	979	923	(114)
Earnings before income tax	46,230	32,672	15,869
Income tax expense	11,097	8,351	4,666
Net income	35,133	24,321	11,203
Income attributable to non-controlling interest	(1,313)	(6,449)	(1,545)
Net income attributable to Gentherm, Inc.	33,820	17,872	9,658
Convertible preferred stock dividends	(1,622)	(6,711)	(8,228)
Net income attributable to common shareholders	$ 32,198	$ 11,161	$ 1,430
Basic earnings per share	$ 0.96	$ 0.39	$ 0.06
Diluted earnings per share	$ 0.94	$ 0.39	$ 0.06
Weighted average number of shares—basic	33,652,646	28,352,864	22,605,518
Weighted average number of shares—diluted	34,123,641	28,862,463	23,454,622