Commitments and Contingencies (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended	6 Months Ended		12 Months Ended
	Mar. 31, 2011	Dec. 31, 2014 gal	Jun. 30, 2014	Dec. 31, 2014 agreement gal	Dec. 31, 2013	Dec. 31, 2012
Contingencies And Commitments [Line Items]
Total rent expense under operating leases				$ 27,466	$ 30,893	$ 19,424
Amount of surety bonds to secure asset closure and retirement requirements		342,591		342,591	304,416
Amount of surety bonds to secure performance under collection contracts and landfill operating agreements		94,385		94,385	89,196
Percentage of interest in company that issues financial surety bonds				9.90%
Outstanding amount of financial surety bonds		179,204		179,204	163,187
Environmental remediation reserve-current portion		3,023		3,023	3,226
Environmental remediation reserve-Non-current portion		725		725	725
Unrecorded unconditional purchase obligation, remaining volume		8,700,000		8,700,000
Purchase commitment		29,024		29,024
Amount of monetary damages County is seeking				2,962
Pre-judgment interest				10.00%
Term of unilateral option to extend contract				5 years
Period to cure the default	30 days
Current annual impact to pre-tax earnings resulting from termination of MDSI's contracts with Madera County				2,300
Number of collective bargaining agreements expired or set to expire				5
Allocable portion of liability of underfunded trust		5,000	866
The total deficiency assessments issued to the former members of the trust		32,000		32,000
Estimated clean up costs		$ 342,000		$ 342,000
Minimum [Member]
Contingencies And Commitments [Line Items]
Range for non-cancelable operating leases				1 year
Maximum [Member]
Contingencies And Commitments [Line Items]
Range for non-cancelable operating leases				45 years