Acquisitions - Pro Forma (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Business Acquisition, Pro Forma Information
Net Sales	$ 1,280,940	[1]	$ 1,144,020	[1]
Net income attributable to TriMas Corporation	$ 35,850	[1]	$ 54,540	[1]

[1] 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.