FAIR VALUE MEASUREMENTS (Details) (Measured on a Recurring Basis:, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2013
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Liabilities at fair value	$ 0
Transfers of assets
Amounts transferred from Level 1 to Level 2	0
Amounts transferred from Level 2 to Level 1	0
Amounts transferred in Level 3	0
Amounts transferred out of Level 3	0
Total
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	1,512,147
Total | Government agency and government-sponsored enterprises residential mortgage-backed securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	913,322
Total | Covered private label CMOs
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	39,378
Total | Municipal securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	439,635
Total | Corporate securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	82,106
Total | Other securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	37,706
Level 1
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	514
Level 1 | Other securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	514
Level 2
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	1,472,255
Level 2 | Government agency and government-sponsored enterprises residential mortgage-backed securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	913,322
Level 2 | Municipal securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	439,635
Level 2 | Corporate securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	82,106
Level 2 | Other securities
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	37,192
Level 3
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	39,378
Level 3 | Covered private label CMOs
Assets measured and recorded at fair value on a recurring and nonrecurring basis
Assets at fair value	$ 39,378