Organization, Business and Summary of Significant Accounting Policies (Reconciliation of Final Capping, Closure and Post-Closure Liability Balance) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Organization, Business and Summary of Significant Accounting Policies [Abstract]
Final capping, closure and post-closure liability at the beginning of the period	$ 50,128	$ 46,473
Adjustments to final capping, closure and post-closure liabilities	4,176	(3,528)
Liabilities incurred	3,846	4,668
Accretion expense associated with landfill obligations	3,408	2,749
Closure payments	(178)	(234)
Assumption of closure liabilities from acquisitions	120
Final capping, closure and post-closure liability at the end of the period	$ 61,500	$ 50,128