LOANS & ALLOWANCE FOR LOAN LOSSES - UNPAID PRINCIPAL BALANCE FOR PERFORMING AND NONPERFORMING (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Jun. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 5,001,271	$ 3,592,880
Single Family, Mortgage
Financing Receivable, Recorded Investment [Line Items]
Gross loans	2,980,795	1,918,626
Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	3,604	12,690
Warehouse & Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	385,413	370,717
Multi-family
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,185,531	978,511
Commercial real estate secured
Financing Receivable, Recorded Investment [Line Items]
Gross loans	61,403	24,061
Recreational Vehicles and Autos
Financing Receivable, Recorded Investment [Line Items]
Gross loans	13,140	14,740
Factoring
Financing Receivable, Recorded Investment [Line Items]
Gross loans	122,200	118,945
Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	248,584	152,619
Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	601	1,971
Performing Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Gross loans	4,970,440	3,572,495
Performing Financing Receivable | Single Family, Mortgage
Financing Receivable, Recorded Investment [Line Items]
Gross loans	2,957,953	1,906,230
Performing Financing Receivable | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	3,595	12,522
Performing Financing Receivable | Warehouse & Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	385,413	370,717
Performing Financing Receivable | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,180,132	974,209
Performing Financing Receivable | Commercial real estate secured
Financing Receivable, Recorded Investment [Line Items]
Gross loans	59,275	21,076
Performing Financing Receivable | Recreational Vehicles and Autos
Financing Receivable, Recorded Investment [Line Items]
Gross loans	12,687	14,206
Performing Financing Receivable | Factoring
Financing Receivable, Recorded Investment [Line Items]
Gross loans	122,200	118,945
Performing Financing Receivable | Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	248,584	152,619
Performing Financing Receivable | Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	601	1,971
Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Gross loans	30,831	20,385
Nonperforming | Single Family, Mortgage
Financing Receivable, Recorded Investment [Line Items]
Gross loans	22,842	12,396
Nonperforming | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	9	168
Nonperforming | Warehouse & Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Nonperforming | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Gross loans	5,399	4,302
Nonperforming | Commercial real estate secured
Financing Receivable, Recorded Investment [Line Items]
Gross loans	2,128	2,985
Nonperforming | Recreational Vehicles and Autos
Financing Receivable, Recorded Investment [Line Items]
Gross loans	453	534
Nonperforming | Factoring
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Nonperforming | Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Nonperforming | Other
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 0	$ 0