INCOME TAXES - Taxable Income Reconciliation (Details) - USD ($)	3 Months Ended				12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Net income (loss)	$ 1,474,767	$ 11,315,000	$ 11,315,000	$ 11,315,000
REIT Operation
Income Tax Disclosure [Line Items]
Net income (loss)	(1,311,000)		(12,559,000)
Five Oaks Investment Corp
Income Tax Disclosure [Line Items]
Net income (loss)	1,411,000		12,829,000
Subsidiaries
Income Tax Disclosure [Line Items]
Net income (loss)	100,000		270,000		$ 1,300,000
Capitalized transaction fees	(10,000)		(10,000)
Unrealized gain (loss)	380,000		(50,000)
Deferred income	0		52,000
Tax income of taxable subsidiary before utilization of net operating losses	470,000		262,000
Current state tax expense	(102,000)		0
Utilization of net operating losses	(68,000)		(262,000)
Net tax income of taxable subsidiary	$ 300,000		$ 0