LOANS & ALLOWANCE FOR CREDIT LOSSES - UNPAID PRINCIPAL BALANCE FOR PERFORMING AND NONACCRUAL (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 19,825,834	$ 19,802,811
Nonaccrual loans to total loans	0.89%	0.57%
Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 4,151,583	$ 4,178,832
Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,647,469	3,861,931
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,256,265	6,088,622
Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,354,752	5,241,766
Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	415,765	431,660
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total	19,649,136	19,689,452
Performing | Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,092,504	4,133,121
Performing | Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,616,032	3,826,877
Performing | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,215,663	6,062,520
Performing | Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,311,156	5,237,746
Performing | Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	413,781	429,188
Nonaccrual
Financing Receivable, Credit Quality Indicator [Line Items]
Total	176,698	113,359
Nonaccrual | Single Family - Mortgage & Warehouse
Financing Receivable, Credit Quality Indicator [Line Items]
Total	59,079	45,711
Nonaccrual | Multifamily and Commercial Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total	31,437	35,054
Nonaccrual | Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	40,602	26,102
Nonaccrual | Commercial & Industrial - Non-RE
Financing Receivable, Credit Quality Indicator [Line Items]
Total	43,596	4,020
Nonaccrual | Auto & Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,984	$ 2,472