INVESTMENTS - Summary of Held-To-Maturity and Available-For-Sale Investment Securities (Details) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Investment Holdings [Line Items] |
|
|
| Total |
$ 628,497
|
$ 726,259
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
17,591
|
7,911
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
(337)
|
(2,219)
|
| Held-to-Maturity Market Value |
645,751
|
731,951
|
| Total |
1,110,784
|
1,203,065
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
14,961
|
6,078
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
(5,251)
|
(18,501)
|
| Investment securities available-for-sale |
1,120,494
|
1,190,642
|
| U.S. Treasuries |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
0
|
0
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
0
|
0
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
0
|
0
|
| Held-to-Maturity Market Value |
0
|
0
|
| Total |
98
|
98
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
4
|
0
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
0
|
(1)
|
| Investment securities available-for-sale |
102
|
97
|
| Securities of U.S. government agencies and corporations |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
13,811
|
15,486
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
389
|
121
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
0
|
0
|
| Held-to-Maturity Market Value |
14,200
|
15,607
|
| Total |
7,471
|
8,183
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
226
|
157
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
0
|
0
|
| Investment securities available-for-sale |
7,697
|
8,340
|
| Mortgage-backed securities |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
591,224
|
678,318
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
16,639
|
7,452
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
(337)
|
(1,999)
|
| Held-to-Maturity Market Value |
607,526
|
683,771
|
| Total |
662,535
|
775,285
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
8,714
|
2,708
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
(2,241)
|
(12,926)
|
| Investment securities available-for-sale |
669,008
|
765,067
|
| Obligations of state and other political subdivisions |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
23,462
|
27,646
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
563
|
338
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
0
|
(99)
|
| Held-to-Maturity Market Value |
24,025
|
27,885
|
| Total |
119,168
|
105,212
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
3,574
|
2,655
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
(502)
|
(730)
|
| Investment securities available-for-sale |
122,240
|
107,137
|
| Asset-backed Securities [Member] |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
0
|
0
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
0
|
0
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
0
|
0
|
| Held-to-Maturity Market Value |
0
|
0
|
| Total |
286,427
|
236,411
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
1,508
|
35
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
(1,944)
|
(3,445)
|
| Investment securities available-for-sale |
285,991
|
233,001
|
| Other securities |
|
|
| Investment Holdings [Line Items] |
|
|
| Total |
0
|
4,809
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Gain |
0
|
0
|
| Held-to-maturity Securities, Accumulated Unrecognized Holding Loss |
0
|
(121)
|
| Held-to-Maturity Market Value |
0
|
4,688
|
| Total |
35,085
|
77,876
|
| Available for Sale Securities Gross Unrealized Gain Accumulated In Investments |
935
|
523
|
| Available for Sale Securities Gross Unrealized Loss Accumulated In Investments |
(564)
|
(1,399)
|
| Investment securities available-for-sale |
$ 35,456
|
$ 77,000
|