SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

Schedule of asset classification and estimated useful life

The Company depreciates and amortizes the cost of these assets, using the straight-line method as follows:

Asset Classification	Estimated Useful Life
Buildings and building improvements
Buildings	30–40 years
Land, leasehold and building improvements	5–40 years
Camp equipment	12–15 years
Vehicles	3–12 years
Equipment
Capitalized software and computer equipment	3 years
Solar equipment	20 years
Containers and railcars	15–20 years
All other equipment	8–10 years
Furniture and fixtures	5–8 years

Schedule of Property, Plant and Equipment, Landfill Assets [Table Text Block]

As of December 31, 2011, the Company had 11 active landfill sites (including the Company's two non-commercial landfills), which have estimated remaining lives (based on anticipated waste volumes and remaining highly probable airspace) as follows:

		Remaining Lives (Years)	Remaining Highly Probable Airspace (cubic yards) (in thousands)
Facility Name	Location		Permitted	Unpermitted	Total
Altair	Texas	17	917	—	917
Buttonwillow	California	36	8,358	—	8,358
Deer Park	Texas	10	411	—	411
Deer Trail	Colorado	17	711	—	711
Grassy Mountain	Utah	22	2,244	—	2,244
Kimball	Nebraska	12	335	—	335
Lambton	Ontario	82	193	6,212	6,405
Lone Mountain	Oklahoma	26	3,631	—	3,631
Ryley	Alberta	6	901	—	901
Sawyer	North Dakota	15	912	—	912
Westmorland	California	64	2,732	—	2,732
			21,345	6,212	27,557

Remaining Highly Probable Airspace [Table Text Block]

The following table presents the remaining highly probable airspace from January 1, 2009 through December 31, 2011 (in thousands of cubic yards):

	2011		2010		2009
Remaining capacity at January 1,	28,557		25,765		28,308
Addition (reduction) of highly probable airspace	102		3,905		(1,635	)
Consumed	(1,102	)	(1,113	)	(908	)
Remaining capacity at December 31,	27,557		28,557		25,765

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The components of accumulated other comprehensive income were as follows (in thousands):

	December 31,
	2011			2010			2009
Cumulative translation adjustment of foreign currency statements	$	32,702		$	50,966		$	26,430
Unrealized gain (loss) on long-term investments (net of deferred taxes of $155, ($50) and ($109), respectively)	(348		)	459			1,010
Unfunded pension liability (net of deferred taxes of $283, $225 and $201, respectively)	(1,001		)	(666		)	(611		)
	$	31,353		$	50,759		$	26,829