DEPOSITS (Deposit Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deposit Liabilities [Line Items]
Non-interest-bearing checking	$ 1,115,346	$ 981,240
Non-interest-bearing accounts, percent of total	30.80%	27.60%
Interest-bearing checking	422,910	410,316
Interest-bearing checking, percent of total	11.70%	11.50%
Regular savings accounts	798,764	727,957
Regular savings accounts, percent of total	22.10%	20.50%
Money market accounts	408,211	408,998
Money market accounts, percent of total	11.30%	11.50%
Total transaction and saving accounts	2,745,231	2,528,511
Total transaction and saving accounts, percent of total	75.90%	71.10%
Certificates of deposit:
Total certificates of deposit	872,695	1,029,293
Total certificate accounts, percent of total	24.10%	28.90%
Total deposits	3,617,926	3,557,804	3,475,654	3,591,198
Total deposits, percent of total	100.00%	100.00%
Included in total deposits:
Public transaction accounts	87,521	79,955
Public fund transaction accounts, percent of total	2.40%	2.20%
Public interest-bearing certificates	51,465	60,518
Public fund interest-bearing certificates, percent of total	1.40%	1.70%
Total public deposits	138,986	140,473
Total public deposits, percent of total	3.80%	3.90%
Total brokered deposits	4,291	15,702
Total brokered deposits, percent of total	0.10%	0.40%
Up to 1.00% [Member]
Certificates of deposit:
Total certificates of deposit	723,891	792,674
Total certificate accounts, percent of total	20.00%	22.30%
Included in total deposits:
Certificates of deposit, interest rate, upper range limit	1.00%
1.01% to 2.00% [Member]
Certificates of deposit:
Total certificates of deposit	95,663	155,144
Total certificate accounts, percent of total	2.60%	4.30%
Included in total deposits:
Certificates of deposit, interest rate, lower range limit	1.01%
Certificates of deposit, interest rate, upper range limit	2.00%
2.01% to 3.00% [Member]
Certificates of deposit:
Total certificates of deposit	43,062	59,094
Total certificate accounts, percent of total	1.20%	1.60%
Included in total deposits:
Certificates of deposit, interest rate, lower range limit	2.01%
Certificates of deposit, interest rate, upper range limit	3.00%
3.01% to 4.00% [Member]
Certificates of deposit:
Total certificates of deposit	6,663	12,881
Total certificate accounts, percent of total	0.20%	0.40%
Included in total deposits:
Certificates of deposit, interest rate, lower range limit	3.01%
Certificates of deposit, interest rate, upper range limit	4.00%
4.01% and greater [Member]
Certificates of deposit:
Total certificates of deposit	$ 3,416	$ 9,500
Total certificate accounts, percent of total	0.10%	0.30%
Included in total deposits:
Certificates of deposit, interest rate, lower range limit	4.01%