INCOME TAXES - Components of Tax Provision by Jurisdiction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax expense/(benefit):
Federal	$ (2,000)	$ (500)	$ 2,200
State and local	(100)	(100)	500
Current income tax expense (benefit)	(2,100)	(600)	2,700
Deferred income tax expense/(benefit):
Federal	51,200	22,100	(500)
State and local	1,000	2,400	(100)
Foreign	0	0	(100)
Deferred income tax expense (benefit)	52,178	24,547	(677)
Income tax expense	$ 50,118	$ 23,935	$ 2,004