Acquisitions - Pro Forma (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Business Acquisition, Pro Forma Information
Net Sales	$ 1,548,220,000	[1]	$ 1,442,490,000	[1]	$ 1,280,940,000	[2]	$ 1,144,020,000	[2]
Net income attributable to TriMas Corporation	69,430,000	[1]	76,260,000	[1]	35,850,000	[2]	54,540,000	[2]
Allfast Fasteners [Member]
Business acquisition, pre-tax pro-forma amortization expense	6,000,000		6,800,000
Business acquisition, pre-tax pro-forma interest expense	$ 4,900,000		$ 7,100,000

[1] (a)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.

[2] The supplemental pro forma results reflect certain adjustments, such as adjustments for acquisition costs incurred and purchase accounting adjustments related to step-up in value and subsequent amortization of inventory and intangible assets