Business Combinations, Discontinued Operations and Related Transactions - Summary of Operations of Disposed Furniture Components Business (Detail) (CompX, Discontinued operations, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
CompX | Discontinued operations
Business Combinations Discontinued Operations And Related Transactions [Line Items]
Net sales	$ 60.7
Operating income	7.4
Income before taxes	7.2
Income tax expense	3.5
Income from discontinued operations, net of tax	$ 3.7