Accrued Final Capping, Closure and Post Closure (Tables)

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

Changes to Accrued Capping, Closure and Post-Closure Liabilities

The changes to accrued final capping, closure and post-closure liabilities for the six months ended June 30, 2015 and 2014 are as follows:

	Six Months Ended June 30,
	2015			2014
Beginning balance	$	39,829		$	46,326
Obligations incurred		1,116			1,640
Revisions in estimates (1)		—			(3,728	)
Accretion expense		1,665			1,876
Obligations settled (2)		(984	)		(705	)
Ending balance	$	41,626		$	45,409

(1) The revisions in estimates for final capping, closure and post-closure consisted of changes in cost estimates and the timing of final capping and closure events, as well as changes to expansion airspace and tonnage placement assumptions.

(2) Includes amounts that are being processed through accounts payable as a part of our disbursement cycle.