INVESTMENT IN EQUITY SECURITIES (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Number of investment shares acquired (in shares)			4.1
Purchase of investment securities			$ 48,200
Investment in equity securities	$ 41,652			$ 49,153	$ 49,200
Unrealized loss on investment in equity securities	(7,501)	$ 0
Unrealized gain on investment in equity securities, net of income tax provision		12,723
Investment income, dividend	$ 600	$ 600