SECURITIES - Schedule of Unrealized Loss and Fair Value on Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value
Less than 12 months	$ 345,605	$ 664,476
12 months or longer	266,758	198,397
Total	612,363	862,873
Unrealized Losses
Less than 12 months	(5,092)	(13,451)
12 months or longer	(5,453)	(4,992)
Total	(10,545)	(18,443)
Collateralized Loan Obligations [Member]
Fair Value
Less than 12 months	9,966	8,152
12 months or longer	9,973	51,694
Total	19,939	59,846
Unrealized Losses
Less than 12 months	(34)	(41)
12 months or longer	(7)	(938)
Total	(41)	(979)
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	205,658	327,759
12 months or longer	48,199	5,387
Total	253,857	333,146
Unrealized Losses
Less than 12 months	(2,975)	(5,991)
12 months or longer	(616)	(75)
Total	(3,591)	(6,066)
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Fair Value
Less than 12 months	87,147	234,175
12 months or longer	168,324	58,912
Total	255,471	293,087
Unrealized Losses
Less than 12 months	(1,438)	(5,599)
12 months or longer	(4,077)	(2,096)
Total	(5,515)	(7,695)
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	3,119	7,934
12 months or longer	0	0
Total	3,119	7,934
Unrealized Losses
Less than 12 months	(9)	(102)
12 months or longer	0	0
Total	(9)	(102)
Private mortgage backed securities [Member]
Fair Value
Less than 12 months	0	0
12 months or longer	6,864	36,848
Total	6,864	36,848
Unrealized Losses
Less than 12 months	0	0
12 months or longer	(153)	(900)
Total	(153)	(900)
Private collateralized mortgage obligations [Member]
Fair Value
Less than 12 months	0	1,460
12 months or longer	26,129	38,417
Total	26,129	39,877
Unrealized Losses
Less than 12 months	0	0
12 months or longer	(488)	(816)
Total	(488)	(816)
Obligations of state and political subdivisions [Member]
Fair Value
Less than 12 months	15,716	39,321
12 months or longer	2,916	0
Total	18,632	39,321
Unrealized Losses
Less than 12 months	(287)	(895)
12 months or longer	(98)	0
Total	(385)	(895)
Corporate and other debt securities [member]
Fair Value
Less than 12 months	12,873	33,008
12 months or longer	2,388	0
Total	15,261	33,008
Unrealized Losses
Less than 12 months	(164)	(517)
12 months or longer	(4)	0
Total	(168)	(517)
Private commercial mortgage backed securities [Member]
Fair Value
Less than 12 months	11,126	12,667
12 months or longer	1,965	7,139
Total	13,091	19,806
Unrealized Losses
Less than 12 months	(185)	(306)
12 months or longer	(10)	(167)
Total	$ (195)	$ (473)