BASIS OF PRESENTATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Error Corrections and Prior Period Adjustments Restatement
Debt issuance costs	$ (3,039)		$ (3,276)
Net income	$ 50,815	$ 63,270
Immaterial Error Correction
Error Corrections and Prior Period Adjustments Restatement
Accrued payroll liability error in prior periods		2,800
Immaterial Error Correction | Adjustment
Error Corrections and Prior Period Adjustments Restatement
Net income		1,800
Immaterial Error Correction | Deferred Revenue and Other Current Liabilities
Error Corrections and Prior Period Adjustments Restatement
Accrued payroll liability error in prior periods		$ 2,800
Accounting Standards Update 2015-03 | Other long-term assets
Error Corrections and Prior Period Adjustments Restatement
Debt issuance costs			3,300
Accounting Standards Update 2015-03 | Long-term debt
Error Corrections and Prior Period Adjustments Restatement
Debt issuance costs			$ (3,300)