Consolidated Statement of Shareholders' Equity Statement (USD $) In Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income [Member]
Balances at Dec. 31, 2011	$ 173,790	$ 350	$ 538,610	$ (404,750)	$ 39,580
Net income attributable to TriMas Corporation	47,820			47,820
Other comprehensive income	1,150				1,150
Proceeds from sale of common stock	79,040	40	79,000
Shares surrendered upon vesting of options and restricted stock awards to cover tax obligations	(990)		(990)
Stock option exercises and restricted stock vesting	5,680		5,680
Excess tax benefits from stock based compensation	2,310		2,310
Non-cash compensation expense	6,640		6,640
Balances at Sep. 30, 2012	$ 315,440	$ 390	$ 631,250	$ (356,930)	$ 40,730