PREMISES AND EQUIPMENT, NET - Summary of Premise and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
PREMISES AND EQUIPMENT, NET
Premises and equipment, gross	$ 47,649	$ 59,311
Less: Accumulated depreciation and amortization	(45,940)	(55,089)
Total	1,709	4,222
Computer hardware and software
PREMISES AND EQUIPMENT, NET
Premises and equipment, gross	46,519	49,339
Leasehold improvements
PREMISES AND EQUIPMENT, NET
Premises and equipment, gross	1,011	5,794
Furniture and fixtures
PREMISES AND EQUIPMENT, NET
Premises and equipment, gross	102	3,832
Office equipment and other
PREMISES AND EQUIPMENT, NET
Premises and equipment, gross	$ 17	$ 346