Other Long-Term Liabilities - Other Long-Term Liabilities (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Other Liabilities [Line Items]
Environmental	$ 19,033,000	$ 18,533,000
Unrecognized tax benefits, interest and penalties	657,000	802,000
Long-term incentive plan	220,000	1,242,000
Acquisition earn-out, long-term	57,000
Other long-term liabilities	$ 19,967,000	$ 20,577,000