Basis of Presentation - Cequent Spinoff (Details) $ in Thousands		9 Months Ended
	Jun. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Jun. 25, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percent of outstanding shares distributed as of spinoff	100.00%
Number of TriMas shares per one Horizon share in spinoff				2.5
Cash dividend paid to former parent	$ 214,500	$ 0	$ 214,500