LONG-TERM INCENTIVE COMPENSATION (Details) - Restricted Stock - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock based compensation expense	$ 4,017	$ 2,989	$ 7,695	$ 6,468
Service condition stock based compensation expense | The Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock based compensation expense	2,220	1,737	4,403	3,551
Performance condition stock based compensation expense | The Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock based compensation expense	1,600	1,436	2,954	2,685
Stock based compensation expense under the Plan | The Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock based compensation expense	3,820	3,173	7,357	6,236
Canada EB Plan stock based compensation expense | Canada EB Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock based compensation expense	$ 197	$ (184)	$ 338	$ 232