SERVICER ADVANCE INVESTMENTS - Schedule of Interest Income Related to Investments in Servicer Advances (Details) - Servicer Advance Investments - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investment [Line Items]
Interest income, gross of amounts attributable to servicer compensation	$ 83,979	$ 161,601	$ 290,933	$ 581,231
Amounts attributable to base servicer compensation	(38,549)	(15,276)	(145,055)	(68,184)
Amounts attributable to incentive servicer compensation	84,724	(45,197)	300,788	(255,170)
Interest income from Servicer Advance Investments	130,154	$ 101,128	446,666	$ 257,877
Retrospective adjustment	$ 46,500		$ 204,100
Servicing asset fee, basis bps	0.13%		0.13%