GOODWILL AND OTHER INTANGIBLE ASSETS - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Beginning Balance	$ 3,758,177	$ 2,418,832
Net increase in goodwill related to current year	33,593	1,450,950
Purchase accounting allocation adjustments for prior year acquisitions	(224,123)	(28,277)
Goodwill other changes		(440)
Changes due to foreign currency fluctuations	(9,364)	(82,888)
Ending Balance	3,558,283	3,758,177
Domestic Regulated Waste and Compliance Services
Goodwill [Roll Forward]
Beginning Balance	2,612,185	1,467,969
Net increase in goodwill related to current year	29,171	1,150,437
Purchase accounting allocation adjustments for prior year acquisitions	(128,076)	(6,221)
Ending Balance	2,513,280	2,612,185
International Regulated Waste and Compliance Services
Goodwill [Roll Forward]
Beginning Balance	785,902	614,783
Net increase in goodwill related to current year	4,422	273,519
Purchase accounting allocation adjustments for prior year acquisitions	(97,197)	(19,072)
Goodwill other changes		(440)
Changes due to foreign currency fluctuations	(9,364)	(82,888)
Ending Balance	683,763	785,902
Other Segments
Goodwill [Roll Forward]
Beginning Balance	360,090	336,080
Net increase in goodwill related to current year		26,994
Purchase accounting allocation adjustments for prior year acquisitions	1,150	(2,984)
Ending Balance	$ 361,240	$ 360,090