VARIABLE INTEREST ENTITIES - Schedule of Financial Condition of VIEs Reflected in Consolidated Statements of Financial Condition (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets
Mortgage servicing rights	$ 1,108,937	$ 544,562	[1]
Interests in MSR	85,653	69,316	[1]
Other assets	238,793	197,683	[1]
Total assets	76,185,134	76,764,064	[1]
Liabilities
Other liabilities	456,388	94,423	[1]
Total liabilities	64,706,364	63,568,739	[1]
Consolidated VIEs
Assets
Cash and cash equivalents	8,600	16,200
Consolidated VIEs | MSR VIEs
Assets
Cash and cash equivalents	8,570	16,187
Loans	1,897	2,347
Mortgage servicing rights	9,101	7,254
Interests in MSR	85,653	69,316
Other assets	11,600	10,406
Total assets	116,821	105,510
Liabilities
Payable for unsettled trades	2,155	1,911
Other liabilities	6,100	14,582
Total liabilities	$ 8,255	$ 16,493

[1] (1)Derived from the audited consolidated financial statements at December 31, 2021.