SECURITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available for sale:
Amortized Cost	$ 666,123	$ 808,168
Gross Unrealized Gains	4,838	1,193
Gross Unrealized Losses	(3,960)	(9,158)
Estimated Fair Value	667,001	800,203
Held to maturity:
Amortized Cost	227,266	208,351
Gross Unrealized Gains	5,535	2,867
Gross Unrealized Losses	(230)	(1,215)
Estimated Fair Value	232,571	210,003
Total securities
Amortized Cost	893,389	1,016,519
Gross Unrealized Gains	10,373	4,060
Gross Unrealized Losses	(4,190)	(10,373)
Total securities	899,572	1,010,206
U.S. GSE securities
Available for sale:
Amortized Cost	64,993	63,238
Gross Unrealized Gains	102
Gross Unrealized Losses	(7)	(564)
Estimated Fair Value	65,088	62,674
Held to maturity:
Amortized Cost		7,466
Gross Unrealized Gains		1
Gross Unrealized Losses
Estimated Fair Value		7,467
State and municipal obligations
Available for sale:
Amortized Cost	115,643	87,830
Gross Unrealized Gains	1,772	427
Gross Unrealized Losses	(129)	(322)
Estimated Fair Value	117,286	87,935
Held to maturity:
Amortized Cost	64,058	64,878
Gross Unrealized Gains	2,791	1,715
Gross Unrealized Losses	(5)	(113)
Estimated Fair Value	66,844	66,480
U.S. GSE residential mortgage-backed securities
Available for sale:
Amortized Cost	103,897	201,297
Gross Unrealized Gains	1,424	237
Gross Unrealized Losses	(44)	(1,270)
Estimated Fair Value	105,277	200,264
Held to maturity:
Amortized Cost	13,914	7,609
Gross Unrealized Gains	100
Gross Unrealized Losses		(106)
Estimated Fair Value	14,014	7,503
U.S. GSE residential collateralized mortgage obligations
Available for sale:
Amortized Cost	264,866	321,253
Gross Unrealized Gains	1,014	513
Gross Unrealized Losses	(625)	(3,888)
Estimated Fair Value	265,255	317,878
Held to maturity:
Amortized Cost	66,699	60,933
Gross Unrealized Gains	1,203	617
Gross Unrealized Losses	(44)	(498)
Estimated Fair Value	67,858	61,052
U.S. GSE commercial mortgage-backed securities
Available for sale:
Amortized Cost	6,448	12,491
Gross Unrealized Gains	189	7
Gross Unrealized Losses		(80)
Estimated Fair Value	6,637	12,418
Held to maturity:
Amortized Cost	28,947	23,056
Gross Unrealized Gains	684	210
Gross Unrealized Losses	(57)	(313)
Estimated Fair Value	29,574	22,953
U.S. GSE commercial collateralized mortgage obligations
Available for sale:
Amortized Cost	54,026	64,809
Gross Unrealized Gains	337	9
Gross Unrealized Losses	(91)	(620)
Estimated Fair Value	54,272	64,198
Held to maturity:
Amortized Cost	42,648	33,409
Gross Unrealized Gains	722	282
Gross Unrealized Losses	(124)	(185)
Estimated Fair Value	43,246	33,506
Other asset backed securities
Available for sale:
Amortized Cost	24,250	24,250
Gross Unrealized Gains
Gross Unrealized Losses	(1,940)	(1,879)
Estimated Fair Value	22,310	22,371
Corporate bonds
Available for sale:
Amortized Cost	32,000	33,000
Gross Unrealized Gains
Gross Unrealized Losses	(1,124)	(535)
Estimated Fair Value	30,876	32,465
Held to maturity:
Amortized Cost	11,000	11,000
Gross Unrealized Gains	35	42
Gross Unrealized Losses
Estimated Fair Value	$ 11,035	$ 11,042