Acquisitions - Pro Forma (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2014	Dec. 31, 2013
Business Acquisition, Pro Forma Information
Net Sales	[1]	$ 936,440	$ 853,590
Net income attributable to TriMas Corporation	[1]	49,590	56,550
Allfast Fasteners [Member]
Business acquisition, pre-tax pro-forma amortization expense		6,000	6,800
Business acquisition, pre-tax pro-forma interest expense		$ 4,900	$ 7,100

[1] The supplemental pro forma results reflect certain material adjustments, as follows:1.Pre-tax pro forma adjustments for amortization expense of $6.0 million and $6.8 million for the years ended December 31, 2014 and December 31, 2013 on the intangible assets associated with the acquisition. 2.Pre-tax pro forma adjustments of $4.9 million and $7.1 million for the years ended December 31, 2014 and December 31, 2013, respectively, to reflect interest expense incurred on the incremental term loan A and revolver borrowings incurred in order to fund the acquisition.