LOANS (covered) - Investment in Covered Impaired Loans, excluding Loans Accounted for under FASB ASC Topic 310-30 (Detail) (Covered Loans, Loans Excluded from FASB ASC Topic 310-30, Loans with no related allowance recorded, USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 8,420	$ 11,160
Unpaid Principal Balance	13,683	17,050
Related Allowance	0	0
Average Recorded Investment	9,791	13,945
Interest Income Recognized	48	58
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment	5,283	7,203
Unpaid Principal Balance	8,143	10,152
Related Allowance	0	0
Average Recorded Investment	6,243	9,873
Interest Income Recognized	43	47
Real estate-commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,476	2,192
Unpaid Principal Balance	4,403	4,002
Related Allowance	0	0
Average Recorded Investment	2,334	2,504
Interest Income Recognized	4	5
Home equity
Financing Receivable, Impaired [Line Items]
Recorded Investment	646	18
Unpaid Principal Balance	1,122	18
Related Allowance	0	0
Average Recorded Investment	1,197	9
Interest Income Recognized	1	0
All other
Financing Receivable, Impaired [Line Items]
Recorded Investment	15
Unpaid Principal Balance	15
Related Allowance	0
Average Recorded Investment	17
Interest Income Recognized	0
Installment
Financing Receivable, Impaired [Line Items]
Recorded Investment		1,747
Unpaid Principal Balance		2,878
Related Allowance		0
Average Recorded Investment		1,559
Interest Income Recognized		$ 6