CLOSURE AND POST-CLOSURE LIABILITIES (Changes in Post-Closure Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Changes to post-closure liabilities
Balance at the beginning of the period	$ 56,249	$ 50,701
Liabilities assumed in acquisitions	2,408	1,676
Measurement period adjustments from prior period acquisitions	657
New asset retirement obligations	1,983	3,151
Accretion	5,103	4,638
Changes in estimates recorded to statement of operations	(2,619)	43
Changes in estimates recorded to balance sheet	3,289	2,942
Expenditures	(2,248)	(6,123)
Currency translation and other	87	(779)
Balance at the end of the period	$ 58,331	$ 56,249
Asset retirement obligations discount rate	6.23%	5.99%
Landfill Retirement Liability
Changes to post-closure liabilities
Balance at the beginning of the period	$ 32,023	$ 29,932
Liabilities assumed in acquisitions	0	0
Measurement period adjustments from prior period acquisitions	0
New asset retirement obligations	1,983	3,151
Accretion	2,705	2,516
Changes in estimates recorded to statement of operations	(1,415)	(162)
Changes in estimates recorded to balance sheet	3,289	2,942
Expenditures	(1,446)	(5,946)
Currency translation and other	69	(410)
Balance at the end of the period	30,630	32,023
Non-Landfill Retirement Liability
Changes to post-closure liabilities
Balance at the beginning of the period	24,226	20,769
Liabilities assumed in acquisitions	2,408	1,676
Measurement period adjustments from prior period acquisitions	657
Accretion	2,398	2,122
Changes in estimates recorded to statement of operations	(1,204)	205
Changes in estimates recorded to balance sheet	0	0
Expenditures	(802)	(177)
Currency translation and other	18	(369)
Balance at the end of the period	$ 27,701	$ 24,226