LOANS & ALLOWANCE FOR CREDIT LOSSES - UNPAID PRINCIPAL BALANCE FOR PERFORMING AND NONACCRUAL (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 17,161,931	$ 16,652,026
Non accrual loans to total loans	0.62%	0.52%
Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 4,313,906	$ 4,173,833
Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,961,981	3,082,225
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,168,626	6,199,818
Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,208,969	2,639,650
Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	506,011	546,264
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,438	10,236
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total	17,055,005	16,564,866
Performing \| Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,277,324	4,143,119
Performing \| Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,923,154	3,047,122
Performing \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,142,524	6,184,966
Performing \| Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,205,980	2,636,661
Performing \| Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	503,625	544,807
Performing \| Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,398	8,191
Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Total	106,926	87,160
Nonaccrual \| Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	36,582	30,714
Nonaccrual \| Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	38,827	35,103
Nonaccrual \| Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	26,102	14,852
Nonaccrual \| Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,989	2,989
Nonaccrual \| Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,386	1,457
Nonaccrual \| Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 40	$ 2,045

Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481598/310-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

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