Details of Certain Balance Sheet Accounts - Other Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Details Of Certain Balance Sheet Accounts [Abstract]
Workers compensation deposits	$ 300,000	$ 200,000
Health insurance deposits	1,200,000	1,200,000
Other miscellaneous deposit	700,000	900,000
Deferred financing fees	2,800,000	2,200,000
Investments	23,800,000	16,900,000
Other	4,400,000	4,900,000
Other assets, net	$ 33,161,000	$ 26,283,000