INCOME TAXES (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Accrued income taxes	$ 700,000	$ 2,600,000
Prepaid taxes	13,700,000	12,400,000
Deferred tax asset relating to capital losses	$ 400,000	5,800,000
Interest and penalties recognized for uncertain tax positions		0
Percentage of applicable cash saving in income tax distributable to specified unitholders	85.00%
Percentage of applicable cash saving in income tax available for the entity	15.00%
Amount due pursuant to tax receivable agreement	$ 1,570,000	1,656,000
Other assets
Income Tax Contingency [Line Items]
Deferred tax liabilities	(6,900,000)	(5,700,000)
Accrued Expenses
Income Tax Contingency [Line Items]
Liability for unrecognized tax benefits for uncertain income tax positions	800,000	800,000
Amount Payable Pursuant to Tax Receivable Agreement
Income Tax Contingency [Line Items]
Amount due pursuant to tax receivable agreement	1,600,000	1,700,000
State and Local Jurisdiction | New York
Income Tax Contingency [Line Items]
Unincorporated business tax payable (receivable)	$ 500,000	$ 500,000