Summary Quarterly Financial Data (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net sales	$ 301,040	$ 335,870	$ 338,430	$ 297,570	$ 259,650	$ 277,660	$ 288,090	$ 258,560	$ 1,272,910	$ 1,083,960	$ 902,460
Gross Profit	78,820	90,140	95,890	78,910	75,650	81,940	88,290	71,820	343,760	317,700	271,050
Income from continuing operations					7,130	16,980	16,010	10,690	36,290	50,810	38,930
Income from discontinued operations, net of income taxes					6,120	1,290	1,080	1,060	0	9,550	6,340
Net income (loss)	(13,090)	19,960	17,170	12,250					36,290	60,360	45,270
Net income (loss) attributable to noncontrolling interests	850	1,290	510	(240)
Net income (loss) attributable to TriMas Corporation	$ (13,940)	$ 18,670	$ 16,660	$ 12,490	$ 13,250	$ 18,270	$ 17,090	$ 11,750	$ 33,880	$ 60,360	$ 45,270
Continuing operations					$ 0.21	$ 0.49	$ 0.47	$ 0.32	$ 0.90	$ 1.48	$ 1.15
Discontinued operations					$ 0.18	$ 0.04	$ 0.03	$ 0.03	$ 0.00	$ 0.28	$ 0.19
Net income (loss) per share	$ (0.36)	$ 0.48	$ 0.45	$ 0.36	$ 0.39	$ 0.53	$ 0.50	$ 0.35	$ 0.90	$ 1.76	$ 1.34
Weighted average shares—basic	39,101,163	39,045,282	37,345,026	34,592,267	34,437,097	34,417,879	34,215,734	33,913,610	37,520,935	34,246,289	33,761,430
Continuing operations					$ 0.20	$ 0.49	$ 0.46	$ 0.31	$ 0.89	$ 1.46	$ 1.13
Discontinued operations					$ 0.18	$ 0.03	$ 0.03	$ 0.03	$ 0.00	$ 0.27	$ 0.18
Net income (loss) per share	$ (0.35)	$ 0.47	$ 0.44	$ 0.36	$ 0.38	$ 0.52	$ 0.49	$ 0.34	$ 0.89	$ 1.73	$ 1.31
Weighted average shares—diluted	39,680,565	39,508,503	37,694,221	35,027,899	34,961,772	34,901,277	34,769,576	34,599,076	37,949,021	34,779,693	34,435,245