SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Assets and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Assets
Margin receivable, net	$ 53,150	$ 55,481
Other receivables	10,635	16,350
Principal and interest receivable	48,373	52,738
Receivable from government agency	41,429	54,706
Call rights	327	337
Derivative assets	2,423	6,762
Servicing fee receivables	60,520	7,405
Ginnie Mae EBO servicer advances receivable, net	8,916	14,829
Due from servicers	38,601	22,134
Ocwen common stock, at fair value	19,259	0
Prepaid expenses	7,308	9,487
Other assets	21,240	4,269
Total Other Assets	312,181	244,498
Accrued Expenses and Other Liabilities
Interest payable	28,821	23,108
Accounts payable	73,017	31,299
Derivative liabilities	697	3,021
Current taxes payable	0	2,314
Due to servicers	24,571	77,148
MSRs purchase price holdback	101,290	60,436
Other liabilities	10,718	8,118
Accrued Expenses and Other Liabilities	$ 239,114	$ 205,444