LOANS & ALLOWANCE FOR CREDIT LOSSES - SCHEDULE OF PAST DUE LOANS (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Jun. 30, 2026
Financing Receivable, Past Due [Line Items]
Total	$ 26,358,461	$ 26,096,037
As a % of total gross loans	100.00%	100.00%
Current
Financing Receivable, Past Due [Line Items]
Total	$ 26,156,771	$ 25,855,526
As a % of total gross loans	99.23%	99.08%
30-59 Days
Financing Receivable, Past Due [Line Items]
Total	$ 40,461	$ 41,874
As a % of total gross loans	0.15%	0.16%
60-89 Days
Financing Receivable, Past Due [Line Items]
Total	$ 28,088	$ 39,145
As a % of total gross loans	0.11%	0.15%
90+ Days
Financing Receivable, Past Due [Line Items]
Total	$ 133,141	$ 159,492
As a % of total gross loans	0.51%	0.61%
Single Family - Mortgage & Warehouse
Financing Receivable, Past Due [Line Items]
Total	$ 4,446,687	$ 4,581,772
Single Family - Mortgage & Warehouse \| Current
Financing Receivable, Past Due [Line Items]
Total	4,354,919	4,517,180
Single Family - Mortgage & Warehouse \| 30-59 Days
Financing Receivable, Past Due [Line Items]
Total	19,117	4,142
Single Family - Mortgage & Warehouse \| 60-89 Days
Financing Receivable, Past Due [Line Items]
Total	17,793	2,755
Single Family - Mortgage & Warehouse \| 90+ Days
Financing Receivable, Past Due [Line Items]
Total	54,858	57,695
Multifamily and Commercial Mortgage
Financing Receivable, Past Due [Line Items]
Total	2,373,026	2,484,290
Multifamily and Commercial Mortgage \| Current
Financing Receivable, Past Due [Line Items]
Total	2,368,423	2,476,985
Multifamily and Commercial Mortgage \| 30-59 Days
Financing Receivable, Past Due [Line Items]
Total	0	3,407
Multifamily and Commercial Mortgage \| 60-89 Days
Financing Receivable, Past Due [Line Items]
Total	2,305	0
Multifamily and Commercial Mortgage \| 90+ Days
Financing Receivable, Past Due [Line Items]
Total	2,298	3,898
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	9,657,946	8,867,851
Commercial Real Estate \| Current
Financing Receivable, Past Due [Line Items]
Total	9,642,038	8,853,128
Commercial Real Estate \| 30-59 Days
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Real Estate \| 60-89 Days
Financing Receivable, Past Due [Line Items]
Total	1,185	0
Commercial Real Estate \| 90+ Days
Financing Receivable, Past Due [Line Items]
Total	14,723	14,723
Commercial & Industrial - Non-RE
Financing Receivable, Past Due [Line Items]
Total	9,160,723	9,495,647
Commercial & Industrial - Non-RE \| Current
Financing Receivable, Past Due [Line Items]
Total	9,076,122	9,347,305
Commercial & Industrial - Non-RE \| 30-59 Days
Financing Receivable, Past Due [Line Items]
Total	18,460	30,302
Commercial & Industrial - Non-RE \| 60-89 Days
Financing Receivable, Past Due [Line Items]
Total	5,646	35,723
Commercial & Industrial - Non-RE \| 90+ Days
Financing Receivable, Past Due [Line Items]
Total	60,495	82,317
Auto & Consumer
Financing Receivable, Past Due [Line Items]
Total	720,079	666,477
Auto & Consumer \| Current
Financing Receivable, Past Due [Line Items]
Total	715,269	660,928
Auto & Consumer \| 30-59 Days
Financing Receivable, Past Due [Line Items]
Total	2,884	4,023
Auto & Consumer \| 60-89 Days
Financing Receivable, Past Due [Line Items]
Total	1,159	667
Auto & Consumer \| 90+ Days
Financing Receivable, Past Due [Line Items]
Total	$ 767	$ 859