SUBSEQUENT EVENTS (Details) - USD ($) $ in Thousands	Oct. 15, 2018	Oct. 17, 2018	Sep. 30, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Carrying Value			$ 813,754	$ 814,139
Two Thousand Thirteen Senior Notes [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Repayments of Long-term Debt	$ 50,000
Carrying Value	$ 500,000
Revolving Credit Facility [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Carrying Value		$ 500,000
Minimum [Member] | Revolving Credit Facility [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Carrying Value		100,000
Maximum [Member] | Revolving Credit Facility [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Carrying Value		$ 200,000