COMMITMENTS, CONTINGENCIES AND OTHER MATTERS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) officer state	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Number of principal shareholders and senior executive officers | officer	3
Rental income, due in next fiscal year	$ 2.1
Rental income, due between one and three years	4.1
Rental income, due after year three	0.2
Annual rent expense	12.5	$ 13.5	$ 17.7
Related party rent expense	1.0	0.9	0.9
Rent expense net of sublease income	$ 0.2	0.4	0.4
Number of states seeking recovery of unclaimed property | state	23
Number of states requesting payments of claimed amounts | state	21
Discontinued NATG and ETG
Loss Contingencies [Line Items]
Annual rent expense	$ 1.1	$ 2.3	$ 6.6