FAIR VALUE OF FINANCIAL ASSETS AND LIABILITIES (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets and liabilities measured at fair value
Available for sale securities:	$ 1,184,564	$ 1,407,999
States and political subdivisions debt securities
Assets and liabilities measured at fair value
Available for sale securities:	190,159	179,357
Corporations debt securities
Assets and liabilities measured at fair value
Available for sale securities:	85,552	158,095
U.S. Government sponsored entities mortgage-backed securities
Assets and liabilities measured at fair value
Available for sale securities:	740,539	927,626
Non-agency collateralized mortgage obligations
Assets and liabilities measured at fair value
Available for sale securities:	167,461	142,046
Other
Assets and liabilities measured at fair value
Available for sale securities:	853	875
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets and liabilities measured at fair value
Total	853	875
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Other
Assets and liabilities measured at fair value
Available for sale securities:	853	875
Recurring basis \| Significant Other Observable Inputs (Level 2)
Assets and liabilities measured at fair value
Total	1,171,503	1,396,885
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Interest rate contracts
Assets and liabilities measured at fair value
Derivatives	507	279
Recurring basis \| Significant Other Observable Inputs (Level 2) \| States and political subdivisions debt securities
Assets and liabilities measured at fair value
Available for sale securities:	177,444	168,839
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporations debt securities
Assets and liabilities measured at fair value
Available for sale securities:	85,552	158,095
Recurring basis \| Significant Other Observable Inputs (Level 2) \| U.S. Government sponsored entities mortgage-backed securities
Assets and liabilities measured at fair value
Available for sale securities:	740,539	927,626
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Non-agency collateralized mortgage obligations
Assets and liabilities measured at fair value
Available for sale securities:	167,461	142,046
Recurring basis \| Significant Unobservable Inputs (Level 3)
Assets and liabilities measured at fair value
Total	12,715	10,518
Recurring basis \| Significant Unobservable Inputs (Level 3) \| States and political subdivisions debt securities
Assets and liabilities measured at fair value
Available for sale securities:	12,715	10,518
Recurring basis \| Fair Value
Assets and liabilities measured at fair value
Total	1,185,071	1,408,278
Recurring basis \| Fair Value \| Interest rate contracts
Assets and liabilities measured at fair value
Derivatives	507	279
Recurring basis \| Fair Value \| States and political subdivisions debt securities
Assets and liabilities measured at fair value
Available for sale securities:	190,159	179,357
Recurring basis \| Fair Value \| Corporations debt securities
Assets and liabilities measured at fair value
Available for sale securities:	85,552	158,095
Recurring basis \| Fair Value \| U.S. Government sponsored entities mortgage-backed securities
Assets and liabilities measured at fair value
Available for sale securities:	740,539	927,626
Recurring basis \| Fair Value \| Non-agency collateralized mortgage obligations
Assets and liabilities measured at fair value
Available for sale securities:	167,461	142,046
Recurring basis \| Fair Value \| Other
Assets and liabilities measured at fair value
Available for sale securities:	$ 853	$ 875