INCOME TAXES - Additional Information (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
		Jan. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Accrued income taxes			$ 3,800	$ 6,100
Prepaid taxes			10,500	11,600
Deferred tax liabilities			(4,671)	0
Deferred tax asset related to capital losses			6,700	2,400
Income tax expense (benefit)			$ 3,300	3,300
Fees and other income		$ 2,500		2,500
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 payable pursuant to tax receivable agreement	[1]		$ 1,559	1,570
Other assets
Income Tax Contingency [Line Items]
Deferred tax liabilities			(2,100)
Deferred tax assets				2,300
Accrued Liabilities
Income Tax Contingency [Line Items]
Liability for unrecognized tax benefits for uncertain income tax positions			200	800
Amount of unrecognized tax benefit released due to statue of limitations			600
Amount Payable Pursuant to Tax Receivable Agreement
Income Tax Contingency [Line Items]
Amount payable pursuant to tax receivable agreement			1,600	1,600
State and Local Jurisdiction | New York State Division of Taxation and Finance
Income Tax Contingency [Line Items]
Unincorporated business tax payable (receivable)			$ 500	$ 500

[1] Includes amounts relating to consolidated variable interest entities. See Note 10.