LOANS HELD FOR INVESTMENT, NET - Deferral Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CARES Act Loan [Abstract]
Principal balances outstanding	$ 9,660,907	$ 9,244,661
One-to-four family residential and cooperative/condominium apartment
CARES Act Loan [Abstract]
Principal balances outstanding	691,586	669,282
Commercial real estate ("CRE")
CARES Act Loan [Abstract]
Principal balances outstanding	4,091,372	3,945,948
Commercial and Industrial ("C&I") Loans
CARES Act Loan [Abstract]
Principal balances outstanding	$ 960,888	$ 933,559

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant