LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Allowance for Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	$ 74,371	$ 76,396	$ 74,258	$ 76,759
PROVISION FOR LOAN LOSSES	0	0	0	0
Recoveries	1,605	1,811	3,246	4,139
Charge-offs	(1,666)	(2,086)	(3,194)	(4,777)
Ending balance	74,310	76,121	74,310	76,121
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	4,323	6,254	4,323	6,254
Allowance collectively evaluated for impairment	69,987	69,867	69,987	69,867
Total allowance for loan losses	74,310	76,121	74,310	76,121
Loans individually evaluated for impairment	44,631	62,488	44,631	62,488
Loans collectively evaluated for impairment	3,717,968	3,227,713	3,717,968	3,227,713
Total loans outstanding	3,762,599	3,290,201	3,762,599	3,290,201	3,418,445
Commercial real estate [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	17,412	14,776	16,759	15,322
PROVISION FOR LOAN LOSSES	2,199	162	2,794	(1,622)
Recoveries	274	378	570	1,964
Charge-offs	(1,001)	(418)	(1,239)	(766)
Ending balance	18,884	14,898	18,884	14,898
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	751	750	751	750
Allowance collectively evaluated for impairment	18,133	14,148	18,133	14,148
Total allowance for loan losses	18,884	14,898	18,884	14,898
Loans individually evaluated for impairment	8,060	10,647	8,060	10,647
Loans collectively evaluated for impairment	1,340,997	1,086,061	1,340,997	1,086,061
Total loans outstanding	1,349,057	1,096,708	1,349,057	1,096,708	1,195,058
Multifamily [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	5,652	5,075	5,306	4,506
PROVISION FOR LOAN LOSSES	113	(102)	459	467
Recoveries	0	0	0	0
Charge-offs	0	0	0	0
Ending balance	5,765	4,973	5,765	4,973
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	850	1,326	850	1,326
Allowance collectively evaluated for impairment	4,915	3,647	4,915	3,647
Total allowance for loan losses	5,765	4,973	5,765	4,973
Loans individually evaluated for impairment	5,705	5,815	5,705	5,815
Loans collectively evaluated for impairment	183,087	131,212	183,087	131,212
Total loans outstanding	188,792	137,027	188,792	137,027
Construction and Land [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	18,620	15,214	17,640	14,991
PROVISION FOR LOAN LOSSES	(1,048)	1,493	(300)	2,050
Recoveries	472	337	704	438
Charge-offs	(207)	(419)	(207)	(854)
Ending balance	17,837	16,625	17,837	16,625
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,291	1,955	1,291	1,955
Allowance collectively evaluated for impairment	16,546	14,670	16,546	14,670
Total allowance for loan losses	17,837	16,625	17,837	16,625
Loans individually evaluated for impairment	7,765	12,723	7,765	12,723
Loans collectively evaluated for impairment	341,860	340,961	341,860	340,961
Total loans outstanding	349,625	353,684	349,625	353,684	351,258
Commercial business [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	11,363	10,011	11,773	9,957
PROVISION FOR LOAN LOSSES	625	527	660	1,124
Recoveries	286	666	579	1,052
Charge-offs	(260)	(398)	(998)	(1,327)
Ending balance	12,014	10,806	12,014	10,806
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	162	216	162	216
Allowance collectively evaluated for impairment	11,852	10,590	11,852	10,590
Total allowance for loan losses	12,014	10,806	12,014	10,806
Loans individually evaluated for impairment	989	2,818	989	2,818
Loans collectively evaluated for impairment	734,139	637,022	734,139	637,022
Total loans outstanding	735,128	639,840	735,128	639,840	682,169
Agricultural Business [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	2,636	2,282	2,841	2,295
PROVISION FOR LOAN LOSSES	(123)	1,213	(678)	1,163
Recoveries	311	310	661	347
Charge-offs	0	0	0	0
Ending balance	2,824	3,805	2,824	3,805
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	0	0	0	0
Allowance collectively evaluated for impairment	2,824	3,805	2,824	3,805
Total allowance for loan losses	2,824	3,805	2,824	3,805
Loans individually evaluated for impairment	0	0	0	0
Loans collectively evaluated for impairment	245,742	233,967	245,742	233,967
Total loans outstanding	245,742	233,967	245,742	233,967	228,291
One- to Four-Family [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	10,913	15,930	11,486	16,475
PROVISION FOR LOAN LOSSES	(1,833)	(557)	(2,215)	(567)
Recoveries	204	3	392	119
Charge-offs	(14)	(402)	(393)	(1,053)
Ending balance	9,270	14,974	9,270	14,974
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,170	1,923	1,170	1,923
Allowance collectively evaluated for impairment	8,100	13,051	8,100	13,051
Total allowance for loan losses	9,270	14,974	9,270	14,974
Loans individually evaluated for impairment	21,133	29,419	21,133	29,419
Loans collectively evaluated for impairment	537,611	523,279	537,611	523,279
Total loans outstanding	558,744	552,698	558,744	552,698
Consumer [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	912	1,238	1,335	1,348
PROVISION FOR LOAN LOSSES	(38)	105	(570)	221
Recoveries	58	117	340	219
Charge-offs	(184)	(449)	(357)	(777)
Ending balance	748	1,011	748	1,011
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	99	84	99	84
Allowance collectively evaluated for impairment	649	927	649	927
Total allowance for loan losses	748	1,011	748	1,011
Loans individually evaluated for impairment	979	1,066	979	1,066
Loans collectively evaluated for impairment	334,532	275,211	334,532	275,211
Total loans outstanding	335,511	276,277	335,511	276,277	295,022
Unallocated [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Beginning balance	6,863	11,870	7,118	11,865
PROVISION FOR LOAN LOSSES	105	(2,841)	(150)	(2,836)
Recoveries	0	0	0	0
Charge-offs	0	0	0	0
Ending balance	6,968	9,029	6,968	9,029
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment	0	0	0	0
Allowance collectively evaluated for impairment	6,968	9,029	6,968	9,029
Total allowance for loan losses	6,968	9,029	6,968	9,029
Loans individually evaluated for impairment	0	0	0	0
Loans collectively evaluated for impairment	0	0	0	0
Total loans outstanding	$ 0	$ 0	$ 0	$ 0