8. ALLOWANCE FOR LOAN AND LEASE LOSSES (Detail) - (Table 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Provision	$ 100	$ 580
Commercial Portfolio Segment [Member]
Beginning Balance	1,351	1,536	1,351	1,536
Provision	(84)	(543)
Loans charged-off	(10)	(48)
Recoveries	74
Ending balance	1,331	945
Ending balance:
Allowance individually evaluated for impairment	542		480
Ending balance:
Allowance collectively evaluated for impairment	789		871
Ending balance	27,327		30,811
Ending balance:
Allowance individually evaluated for impairment	2,390		2,828
Ending balance:
Allowance collectively evaluated for impairment	24,937		27,983
Commercial Real Estate Portfolio Segment [Member]
Beginning Balance	2,526	3,156
Provision	140	370
Loans charged-off		(611)
Recoveries	1	44
Ending balance	2,667	2,959
Ending balance:
Allowance individually evaluated for impairment	871		786
Ending balance:
Allowance collectively evaluated for impairment	1,796		1,740
Ending balance	176,922		180,126
Ending balance:
Allowance individually evaluated for impairment	17,531		19,105
Ending balance:
Allowance collectively evaluated for impairment	159,391		161,021
Multi-Family Real Estate Portfolio Segment [Member]
Beginning Balance	238	198	238	198
Provision	18	102
Loans charged-off		(8)
Recoveries		4
Ending balance	256	296
Ending balance:
Allowance individually evaluated for impairment	125		122
Ending balance:
Allowance collectively evaluated for impairment	131		116
Ending balance	10,311		9,155
Ending balance:
Allowance individually evaluated for impairment	1,673		1,681
Ending balance:
Allowance collectively evaluated for impairment	8,638		7,474
Construction Real Estate Portfolio Segment [Member]
Beginning Balance	594	582	594	3,156
Provision	(164)	(111)
Loans charged-off		(4)
Ending balance	430	467
Ending balance:
Allowance collectively evaluated for impairment	430		594
Ending balance	5,932		6,918
Ending balance:
Allowance individually evaluated for impairment	259		263
Ending balance:
Allowance collectively evaluated for impairment	5,673		6,655
Residential Portfolio Segment [Member]
Beginning Balance	477	609	609
Provision	62	217
Loans charged-off	(38)	(113)
Ending balance	501	713
Ending balance:
Allowance individually evaluated for impairment	165		179
Ending balance:
Allowance collectively evaluated for impairment	336		298
Ending balance	18,888		17,701
Ending balance:
Allowance individually evaluated for impairment	2,382		2,429
Ending balance:
Allowance collectively evaluated for impairment	16,506		15,272
Finance Leases Portfolio Segment [Member]
Beginning Balance	3	79	3	79
Provision		(64)
Loans charged-off		(8)
Ending balance	3	7
Ending balance:
Allowance collectively evaluated for impairment	3		3
Ending balance	1,333		1,509
Ending balance:
Allowance collectively evaluated for impairment	1,333		1,509
Agriculture Portfolio Segment [Member]
Beginning Balance	87	167	87	167
Provision	4	289
Loans charged-off		(202)
Ending balance	91	254
Ending balance:
Allowance collectively evaluated for impairment	91		87
Ending balance	3,327		3,340
Ending balance:
Allowance collectively evaluated for impairment	3,327		3,340
Consumer Portfolio Segment [Member]
Beginning Balance	262	348	262	348
Provision	(8)	435
Loans charged-off	(5)	(410)
Ending balance	249	373
Ending balance:
Allowance individually evaluated for impairment	30		28
Ending balance:
Allowance collectively evaluated for impairment	219		234
Ending balance	7,588		8,569
Ending balance:
Allowance individually evaluated for impairment	242		247
Ending balance:
Allowance collectively evaluated for impairment	7,346		8,322
Unallocated Porfolio Segment [Member]
Beginning Balance	243	366		366
Provision	132	(115)
Ending balance	375	251
Ending balance:
Allowance collectively evaluated for impairment	375		243
Total [ Member]
Beginning Balance	5,781	7,041	5,781	7,041
Provision	100	580
Loans charged-off	(53)	(1,404)
Recoveries	75	48
Ending balance	5,903	6,265
Ending balance:
Allowance individually evaluated for impairment	1,733		1,595
Ending balance:
Allowance collectively evaluated for impairment	4,170		4,186
Ending balance	251,628		258,129
Ending balance:
Allowance individually evaluated for impairment	24,477		26,553
Ending balance:
Allowance collectively evaluated for impairment	$ 227,151		$ 231,576