FAIR VALUE (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets measured at fair value on recurring basis
Available for sale securities	$ 823,515	$ 819,722
U.S. GSE securities
Assets measured at fair value on recurring basis
Available for sale securities	63,833	63,649
State and municipal obligations
Assets measured at fair value on recurring basis
Available for sale securities	115,731	116,165
U.S. GSE residential mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	179,822	158,048
U.S. GSE residential collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	351,488	367,511
U.S. GSE commercial mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	6,284	6,307
U.S. GSE commercial collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	53,345	55,192
Other asset backed securities
Assets measured at fair value on recurring basis
Available for sale securities	22,795	22,553
Corporate bonds
Assets measured at fair value on recurring basis
Available for sale securities	30,217	30,297
Carrying Value
Assets measured at fair value on recurring basis
Available for sale securities	823,515	819,722
Financial Assets: Derivatives	2,752	2,510
Financial Liabilities:
Financial liabilities: Derivatives	1,611	1,670
Recurring basis | Carrying Value
Assets measured at fair value on recurring basis
Available for sale securities	823,515	819,722
Recurring basis | Carrying Value | U.S. GSE securities
Assets measured at fair value on recurring basis
Available for sale securities	63,833	63,649
Recurring basis | Carrying Value | State and municipal obligations
Assets measured at fair value on recurring basis
Available for sale securities	115,731	116,165
Recurring basis | Carrying Value | U.S. GSE residential mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	179,822	158,048
Recurring basis | Carrying Value | U.S. GSE residential collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	351,488	367,511
Recurring basis | Carrying Value | U.S. GSE commercial mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	6,284	6,307
Recurring basis | Carrying Value | U.S. GSE commercial collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	53,345	55,192
Recurring basis | Carrying Value | Other asset backed securities
Assets measured at fair value on recurring basis
Available for sale securities	22,795	22,553
Recurring basis | Carrying Value | Corporate bonds
Assets measured at fair value on recurring basis
Available for sale securities	30,217	30,297
Recurring basis | Carrying Value | Derivatives
Assets measured at fair value on recurring basis
Financial Assets: Derivatives	2,752	2,510
Financial Liabilities:
Financial liabilities: Derivatives	1,611	1,670
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | U.S. GSE securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | State and municipal obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | U.S. GSE residential mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | U.S. GSE residential collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | U.S. GSE commercial mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | U.S. GSE commercial collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | Other asset backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | Corporate bonds
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1) | Derivatives
Assets measured at fair value on recurring basis
Financial Assets: Derivatives
Financial Liabilities:
Financial liabilities: Derivatives
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets measured at fair value on recurring basis
Available for sale securities	823,515	819,722
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. GSE securities
Assets measured at fair value on recurring basis
Available for sale securities	63,833	63,649
Recurring basis | Significant Other Observable Inputs (Level 2) | State and municipal obligations
Assets measured at fair value on recurring basis
Available for sale securities	115,731	116,165
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. GSE residential mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	179,822	158,048
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. GSE residential collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	351,488	367,511
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. GSE commercial mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities	6,284	6,307
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. GSE commercial collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities	53,345	55,192
Recurring basis | Significant Other Observable Inputs (Level 2) | Other asset backed securities
Assets measured at fair value on recurring basis
Available for sale securities	22,795	22,553
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate bonds
Assets measured at fair value on recurring basis
Available for sale securities	30,217	30,297
Recurring basis | Significant Other Observable Inputs (Level 2) | Derivatives
Assets measured at fair value on recurring basis
Financial Assets: Derivatives	2,752	2,510
Financial Liabilities:
Financial liabilities: Derivatives	1,611	1,670
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. GSE securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | State and municipal obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. GSE residential mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. GSE residential collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. GSE commercial mortgage-backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. GSE commercial collateralized mortgage obligations
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | Other asset backed securities
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate bonds
Assets measured at fair value on recurring basis
Available for sale securities
Recurring basis | Significant Unobservable Inputs (Level 3) | Derivatives
Assets measured at fair value on recurring basis
Financial Assets: Derivatives
Financial Liabilities:
Financial liabilities: Derivatives