LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Allowance for Credit Losses) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 82,912	$ 97,401
Provision for loan losses	13,000	35,000
Recoveries	7,466	3,417
Charge-offs	(25,887)	(52,906)
Ending balance	77,491	82,912
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	5,725	7,034
Allowance collectively evaluated for impairment	71,766	75,878
Total allowance for loan losses	77,491	82,912
Loans individually evaluated for impairment	63,123	81,447
Loans collectively evaluated for impairment	3,172,591	3,214,891
Total loans outstanding	3,235,714	3,296,338
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	16,457	11,779
Provision for loan losses	2,009	10,704
Recoveries	921	53
Charge-offs	(4,065)	(6,079)
Ending balance	15,322	16,457
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,149	1,693
Allowance collectively evaluated for impairment	14,173	14,764
Total allowance for loan losses	15,322	16,457
Loans individually evaluated for impairment	11,877	15,393
Loans collectively evaluated for impairment	1,061,345	1,076,035
Total loans outstanding	1,073,222	1,091,428
Multifamily [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,952	3,963
Provision for loan losses	554	671
Recoveries	0	0
Charge-offs	0	(682)
Ending balance	4,506	3,952
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,273	11
Allowance collectively evaluated for impairment	3,233	3,941
Total allowance for loan losses	4,506	3,952
Loans individually evaluated for impairment	5,000	1,997
Loans collectively evaluated for impairment	132,504	137,713
Total loans outstanding	137,504	139,710
Construction and Land [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	18,184	33,121
Provision for loan losses	399	9,789
Recoveries	2,954	1,602
Charge-offs	(6,546)	(26,328)
Ending balance	14,991	18,184
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,456	2,614
Allowance collectively evaluated for impairment	13,535	15,570
Total allowance for loan losses	14,991	18,184
Loans individually evaluated for impairment	8,613	31,290
Loans collectively evaluated for impairment	296,004	287,402
Total loans outstanding	304,617	318,692
Commercial business [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	15,159	24,545
Provision for loan losses	(1,142)	(2,072)
Recoveries	2,425	1,082
Charge-offs	(6,485)	(8,396)
Ending balance	9,957	15,159
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	133	1,404
Allowance collectively evaluated for impairment	9,824	13,755
Total allowance for loan losses	9,957	15,159
Loans individually evaluated for impairment	3,373	12,889
Loans collectively evaluated for impairment	614,676	588,551
Total loans outstanding	618,049	601,440
Agricultural Business [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	1,548	1,846
Provision for loan losses	1,154	159
Recoveries	49	20
Charge-offs	(456)	(477)
Ending balance	2,295	1,548
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	0	592
Allowance collectively evaluated for impairment	2,295	956
Total allowance for loan losses	2,295	1,548
Loans individually evaluated for impairment	0	1,483
Loans collectively evaluated for impairment	230,031	216,688
Total loans outstanding	230,031	218,171
One- To Four- Family [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	12,299	5,829
Provision for loan losses	8,918	16,024
Recoveries	586	356
Charge-offs	(5,328)	(9,910)
Ending balance	16,475	12,299
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	1,656	658
Allowance collectively evaluated for impairment	14,819	11,641
Total allowance for loan losses	16,475	12,299
Loans individually evaluated for impairment	32,494	16,877
Loans collectively evaluated for impairment	549,176	625,624
Total loans outstanding	581,670	642,501
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	1,253	1,794
Provision for loan losses	2,571	189
Recoveries	531	304
Charge-offs	(3,007)	(1,034)
Ending balance	1,348	1,253
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	58	62
Allowance collectively evaluated for impairment	1,290	1,191
Total allowance for loan losses	1,348	1,253
Loans individually evaluated for impairment	1,766	1,518
Loans collectively evaluated for impairment	288,855	282,878
Total loans outstanding	290,621	284,396
Commitments and Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	14,060	14,524
Provision for loan losses	(1,463)	(464)
Recoveries	0	0
Charge-offs	0	0
Ending balance	12,597	14,060
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment	0	0
Allowance collectively evaluated for impairment	12,597	14,060
Total allowance for loan losses	12,597	14,060
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	0	0
Total loans outstanding	$ 0	$ 0