SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Change in Fair Value of Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Income Assets And Liabilities
Excess MSRs	$ (15,078)	$ (16,232)	$ (10,505)
Excess MSRs, equity method investees	1,818	(3,489)	6,800
Servicer advance investments	(9,076)	763	10,288
Real estate and other securities	(400,369)	28,455	2,101
Residential mortgage loans	155,758	(107,604)	(70,914)
Consumer loans	(20,133)	2,816	0
Derivative instruments	298,803	(53,467)	(56,143)
Total change in fair value of investments	$ 11,723	$ (148,758)	$ (118,373)