Landfill Accounting (Reconciliation of Final Capping, Closure and Post-Closure Liability Balance) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Landfill Accounting [Abstract]
Final capping, closure and post-closure liability at the beginning of the period	$ 61,500
Adjustments to final capping, closure and post-closure liabilities	(37)
Liabilities incurred	3,325
Accretion expense associated with landfill obligations	2,756	$ 2,445
Closure payments	(66)
Assumption of closure liabilities from acquisitions	1,061
Final capping, closure and post-closure liability at the end of the period	$ 68,539