Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended									12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Building and improvements [Member] Minimum [Member]	Dec. 31, 2012 Building and improvements [Member] Maximum [Member]	Dec. 31, 2012 Machinery and equipment [Member] Minimum [Member]	Dec. 31, 2012 Machinery and equipment [Member] Maximum [Member]	Dec. 31, 2012 Contran Corporation [Member]	Aug. 01, 2011 Contran Corporation [Member]	Dec. 31, 2012 Contran [Member]	Dec. 31, 2011 Contran [Member]
Ownership Percentage								88.00%	80.00%
Estimated useful lives				10 years	30 years	3 years	15 years
Depreciation expense	$ 11,406,000	$ 11,234,000	$ 12,062,000
Material interest costs capitalized	0	0	0
Income Taxes										9,400,000	200,000
Reserve for uncertain tax positions
Advertising costs	$ 1,400,000	$ 1,800,000	$ 1,400,000