Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Contingencies And Commitments [Line Items]
Rental expense	$ 2,110,000	$ 2,116,000	$ 1,874,000
Letters of credit contingently liable	490,000	473,000
Total environmental accruals	24,367,000	23,209,000
Environmental accrual, long-term portion	19,033,000	18,533,000
Total consideration paid to former executives			1,043,000
Severance Agreements 2010 [Member]
Contingencies And Commitments [Line Items]
Payment period range as of termination date	12 months
Change-of-control period range	12 months
Amount of payment if employees had been terminated	640,000
Severance Agreements 2012 [Member]
Contingencies And Commitments [Line Items]
Payment period range as of termination date	18 months
Change-of-control period range	12 months
Amount of payment if employees had been terminated	315,000
Operable Unit 1 (OU-1) [Member]
Contingencies And Commitments [Line Items]
The estimated cost of the EPA selected remedy	17,600,000
Estimated time to complete EPA selected remedy, low estimate	5 years
Estimated time to complete EPA selected remedy, high estimate	10 years
Operable Unit 2 (OU-2) [Member]
Contingencies And Commitments [Line Items]
The estimated cost of the EPA selected remedy	20,700,000
Estimated time to complete selected EPA remedy	7 years
Pennsauken Site (OU-1 and OU-2) [Member]
Contingencies And Commitments [Line Items]
Payment for past cost as per agreement installment amount	2,141,000
Payment for past cost as per agreement aggregate amount	10,705,000
State of NJ total claim for certain costs	1,800,000
State of NJ total claim for past and future cleanup costs	1,300,000
State of NJ total claim for natural resource damages	500,000
Company offer to resolve State of NJ claim	250,000
Estimated remediation costs, low estimate	20,378,000
Estimated remediation costs, high estimate	32,078,000
Total environmental accruals	20,378,000
Camden Site [Member]
Contingencies And Commitments [Line Items]
Total environmental accruals	2,204,000
Estimated expenditures for fiscal 2013	1,040,000
Wayne Site [Member]
Contingencies And Commitments [Line Items]
Total environmental accruals	1,255,000
Increased in reserve for remedial activities	485,000
Montevideo Minn [Member]
Contingencies And Commitments [Line Items]
Remediation costs component of continuing operations costs	$ 111,000