LOANS AND ALLOWANCE FOR LOAN LOSSES (Impairment Method by Loan Category) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	$ 3,577		$ 3,756
Ending balance: impaired loans collectively evaluated for impairment	11,195		11,675
Ending balance: all other loans collectively evaluated for impairment	63,246		65,602
Balance, end of period	78,018	79,831	81,033	85,633	88,170	91,602
Total loans:
Ending balance: impaired loans individually evaluated for impairment	50,237		57,005
Ending balance: impaired loans collectively evaluated for impairment	104,625		106,578
Ending balance: all other loans collectively evaluated for impairment	2,769,681		2,667,964
Ending balance	2,924,543		2,831,547
Commercial and Industrial [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	108		0
Ending balance: impaired loans collectively evaluated for impairment	658		497
Ending balance: all other loans collectively evaluated for impairment	12,965		12,904
Balance, end of period	13,731	13,871	13,401	13,966	14,168	13,572
Total loans:
Ending balance: impaired loans individually evaluated for impairment	5,794		3,480
Ending balance: impaired loans collectively evaluated for impairment	6,545		7,043
Ending balance: all other loans collectively evaluated for impairment	627,402		590,181
Ending balance	639,741		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	226		232
Ending balance: all other loans collectively evaluated for impairment	6,374		7,113
Balance, end of period	6,600	7,086	7,407	11,412	13,003	14,434
Total loans:
Ending balance: impaired loans individually evaluated for impairment	2,870		3,440
Ending balance: impaired loans collectively evaluated for impairment	1,372		1,474
Ending balance: all other loans collectively evaluated for impairment	119,267		116,748
Ending balance	123,509		121,662
One-to-Four-Family Residential [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	1,221		2,275
Ending balance: impaired loans collectively evaluated for impairment	8,358		8,937
Ending balance: all other loans collectively evaluated for impairment	19,566		21,407
Balance, end of period	29,145	31,220	32,619	35,266	36,660	38,897
Total loans:
Ending balance: impaired loans individually evaluated for impairment	9,866		12,276
Ending balance: impaired loans collectively evaluated for impairment	91,783		93,301
Ending balance: all other loans collectively evaluated for impairment	834,931		815,911
Ending balance	936,580		921,488
Multi-family residential [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	1,960		1,034
Ending balance: impaired loans collectively evaluated for impairment	1,393		1,404
Ending balance: all other loans collectively evaluated for impairment	4,021		2,811
Balance, end of period	7,374	5,269	5,249	4,122	4,202	4,252
Total loans:
Ending balance: impaired loans individually evaluated for impairment	25,558		28,641
Ending balance: impaired loans collectively evaluated for impairment	576		1,107
Ending balance: all other loans collectively evaluated for impairment	90,681		91,556
Ending balance	116,815		121,304
Commercial Real Estate [Member]
Allowance for loan losses:
Ending balance: impaired loans individually evaluated for impairment	288		385
Ending balance: impaired loans collectively evaluated for impairment	559		605
Ending balance: all other loans collectively evaluated for impairment	19,973		21,062
Balance, end of period	20,820	22,043	22,052	20,573	19,720	20,048
Total loans:
Ending balance: impaired loans individually evaluated for impairment	6,149		9,168
Ending balance: impaired loans collectively evaluated for impairment	4,336		3,634
Ending balance: all other loans collectively evaluated for impairment	1,079,661		1,035,432
Ending balance	1,090,146		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	1		0
Ending balance: all other loans collectively evaluated for impairment	347		305
Balance, end of period	348	342	305	294	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	17,739		18,136
Ending balance	$ 17,752		$ 18,155