MORTGAGE SERVICING RIGHTS - Presentation of Activity Related to MSR (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Servicing Asset at Fair Value, Amount [Roll Forward]
Fair value, beginning of period	$ 100,895	$ 378,078
Purchases	468,196	0
Sales	(82,176)	(72,160)
Changes in valuation inputs or assumptions	120,879	(107,517)
Other changes, including realization of expected cash flows	(63,232)	(97,506)
Fair value, end of period	$ 544,562	$ 100,895