LOANS (excluding covered loans) - Loan Delinquency, including Nonaccrual Loans (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 3,012,610	$ 2,968,447
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	823,890	856,981
Real estate-construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	86,173	114,974
Real estate-commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,321,446	1,233,067
Real estate-residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	292,503	287,980
Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	61,590	67,543
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	365,413	358,960
All other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	61,595	48,942
Non Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	19,158	18,789
60 - 89 days past due	6,886	2,964
> 90 days past due	39,851	50,326
Total Past due	65,895	72,079
Current	2,946,715	2,896,368
Total	3,012,610	2,968,447
> 90 days past due and still accruing	143	191
Non Covered Loans | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	948	2,964
60 - 89 days past due	77	96
> 90 days past due	6,385	7,473
Total Past due	7,410	10,533
Current	816,480	846,448
Total	823,890	856,981
> 90 days past due and still accruing	0	0
Non Covered Loans | Real estate-construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	1,968	47
60 - 89 days past due	2	0
> 90 days past due	6,872	17,004
Total Past due	8,842	17,051
Current	77,331	97,923
Total	86,173	114,974
> 90 days past due and still accruing	0	0
Non Covered Loans | Real estate-commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	7,514	4,940
60 - 89 days past due	3,965	2,102
> 90 days past due	18,146	16,654
Total Past due	29,625	23,696
Current	1,291,821	1,209,371
Total	1,321,446	1,233,067
> 90 days past due and still accruing	0	0
Non Covered Loans | Real estate-residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	6,897	8,602
60 - 89 days past due	1,771	236
> 90 days past due	5,963	7,012
Total Past due	14,631	15,850
Current	277,872	272,130
Total	292,503	287,980
> 90 days past due and still accruing	0	0
Non Covered Loans | Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	215	437
60 - 89 days past due	188	53
> 90 days past due	316	355
Total Past due	719	845
Current	60,871	66,698
Total	61,590	67,543
> 90 days past due and still accruing	0	0
Non Covered Loans | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	1,357	1,304
60 - 89 days past due	712	246
> 90 days past due	2,026	1,637
Total Past due	4,095	3,187
Current	361,318	355,773
Total	365,413	358,960
> 90 days past due and still accruing	0	0
Non Covered Loans | All other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	259	495
60 - 89 days past due	171	231
> 90 days past due	143	191
Total Past due	573	917
Current	61,022	48,025
Total	61,595	48,942
> 90 days past due and still accruing	$ 143	$ 191