MORTGAGE SERVICING RIGHTS - MSR Activity Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Servicing Asset at Fair Value, Amount [Roll Forward]
Fair value, beginning of period	$ 1,748,209	$ 544,562
Purchases	36,630	421,012
Changes in valuation inputs or assumptions	30,207	158,963
Other changes, including realization of expected cash flows	(24,066)	(15,600)
Fair value, end of period	$ 1,790,980	$ 1,108,937