SERVICER ADVANCE INVESTMENTS - Schedule of Interest Income Related to Investments in Servicer Advances - Others' Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Others
Investment [Line Items]
Investment in equity	$ 65,392		$ 71,491
Ownership interest	27.20%		27.20%
Net income	$ 1,383	$ 5,820
Others' ownership interest as a percent of total	27.20%	54.20%
Servicer Advance Investments
Investment [Line Items]
Investment in equity	$ 240,340		$ 262,755
Ownership interest	72.80%
Net income	$ 5,085	$ 10,736
Average ownership percentage	72.80%	45.80%