Other Long-Term Liabilities - Other Long-Term Liabilities (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Other Liabilities Disclosure [Abstract]
Environmental	$ 17,200,000	$ 19,033,000
Unrecognized tax benefits, interest and penalties	916,000	657,000
Long-term incentive plan	329,000	220,000
Acquisition earn-out, long-term	25,000	57,000
Other long-term liabilities	$ 18,470,000	$ 19,967,000