MORTGAGE BANKING OPERATIONS - Revenue from Mortgage Servicing (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Servicing income, net:
Servicing fees and other	$ 9,507	$ 9,245	$ 17,828	$ 18,158
Amortization of single family MSRs	(2,515)	(5,181)	(5,940)	(10,874)
Amortization of multifamily and SBA MSRs	(2,337)	(2,133)	(4,049)	(3,477)
Net servicing income	4,655	1,931	7,839	3,807
Risk management, single family MSRs:
Changes in fair value of MSRs due to assumptions	4,323	(5,024)	14,626	6,439
Mortgage servicing rights, risk management	(994)	0	(874)	(1,128)
Loan servicing income	3,661	1,931	6,965	2,679
Servicing contracts
Risk management, single family MSRs:
Net gain (loss) from economic hedging	$ (5,317)	$ 5,024	$ (15,500)	$ (7,567)