LOANS AND ALLOWANCE FOR LOAN LOSSES (Impairment Method by Loan Category) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	$ 2,530	$ 3,756
Ending balance: impaired loans collectively evaluated for impairment	12,005	11,675
Ending balance: all other loans collectively evaluated for impairment	65,296	65,602
Balance, end of period	79,831	81,033	88,170	91,602
Total loans:
Ending balance: impaired loans individually evaluated for impairment	57,081	57,005
Ending balance: impaired loans collectively evaluated for impairment	108,635	106,578
Ending balance: all other loans collectively evaluated for impairment	2,703,863	2,667,964
Ending balance	2,869,579	2,831,547
Commercial and Industrial [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	0	0
Ending balance: impaired loans collectively evaluated for impairment	678	497
Ending balance: all other loans collectively evaluated for impairment	13,193	12,904
Balance, end of period	13,871	13,401	14,168	13,572
Total loans:
Ending balance: impaired loans individually evaluated for impairment	6,190	3,480
Ending balance: impaired loans collectively evaluated for impairment	6,833	7,043
Ending balance: all other loans collectively evaluated for impairment	619,066	590,181
Ending balance	632,089	600,704
Real estate construction and development [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	0	62
Ending balance: impaired loans collectively evaluated for impairment	242	232
Ending balance: all other loans collectively evaluated for impairment	6,844	7,113
Balance, end of period	7,086	7,407	13,003	14,434
Total loans:
Ending balance: impaired loans individually evaluated for impairment	2,881	3,440
Ending balance: impaired loans collectively evaluated for impairment	1,761	1,474
Ending balance: all other loans collectively evaluated for impairment	116,595	116,748
Ending balance	121,237	121,662
One-to-Four-Family Residential [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	1,421	2,275
Ending balance: impaired loans collectively evaluated for impairment	8,858	8,937
Ending balance: all other loans collectively evaluated for impairment	20,941	21,407
Balance, end of period	31,220	32,619	36,660	38,897
Total loans:
Ending balance: impaired loans individually evaluated for impairment	10,515	12,276
Ending balance: impaired loans collectively evaluated for impairment	94,734	93,301
Ending balance: all other loans collectively evaluated for impairment	805,264	815,911
Ending balance	910,513	921,488
Multi-family residential [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	808	1,034
Ending balance: impaired loans collectively evaluated for impairment	1,534	1,404
Ending balance: all other loans collectively evaluated for impairment	2,927	2,811
Balance, end of period	5,269	5,249	4,202	4,252
Total loans:
Ending balance: impaired loans individually evaluated for impairment	28,483	28,641
Ending balance: impaired loans collectively evaluated for impairment	991	1,107
Ending balance: all other loans collectively evaluated for impairment	95,642	91,556
Ending balance	125,116	121,304
Commercial Real Estate [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	301	385
Ending balance: impaired loans collectively evaluated for impairment	693	605
Ending balance: all other loans collectively evaluated for impairment	21,049	21,062
Balance, end of period	22,043	22,052	19,720	20,048
Total loans:
Ending balance: impaired loans individually evaluated for impairment	9,012	9,168
Ending balance: impaired loans collectively evaluated for impairment	4,303	3,634
Ending balance: all other loans collectively evaluated for impairment	1,050,498	1,035,432
Ending balance	1,063,813	1,048,234
Consumer and installment [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	0	0
Ending balance: impaired loans collectively evaluated for impairment	0	0
Ending balance: all other loans collectively evaluated for impairment	342	305
Balance, end of period	342	305	417	399
Total loans:
Ending balance: impaired loans individually evaluated for impairment	0	0
Ending balance: impaired loans collectively evaluated for impairment	13	19
Ending balance: all other loans collectively evaluated for impairment	16,798	18,136
Ending balance	$ 16,811	$ 18,155