SECURITIES - Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Securities in a continuous unrealized loss position with unrealized losses presented by length of time
Less than 12 months, Fair Value	$ 509,184	$ 227,076
Less than 12 months, Unrealized Losses	(8,679)	(1,268)
12 months or longer, Fair Value	8,518	53,428
12 months or longer, Unrealized Losses	(225)	(1,282)
Total Fair Value	517,702	280,504
Total Unrealized Losses	(8,904)	(2,550)
State and municipal
Securities in a continuous unrealized loss position with unrealized losses presented by length of time
Less than 12 months, Fair Value	95,822
Less than 12 months, Unrealized Losses	(2,848)
Total Fair Value	95,822
Total Unrealized Losses	(2,848)
Mortgage-backed securities-residential (Government Sponsored Entity)
Securities in a continuous unrealized loss position with unrealized losses presented by length of time
Less than 12 months, Fair Value	335,668	4,802
Less than 12 months, Unrealized Losses	(4,629)	(33)
12 months or longer, Fair Value		1,367
12 months or longer, Unrealized Losses		(35)
Total Fair Value	335,668	6,169
Total Unrealized Losses	(4,629)	(68)
Collateralized mortgage obligations (Government Sponsored Entity)
Securities in a continuous unrealized loss position with unrealized losses presented by length of time
Less than 12 months, Fair Value	77,694	168,950
Less than 12 months, Unrealized Losses	(1,202)	(644)
12 months or longer, Fair Value	8,518
12 months or longer, Unrealized Losses	(225)
Total Fair Value	86,212	168,950
Total Unrealized Losses	$ (1,427)	(644)
Other securities
Securities in a continuous unrealized loss position with unrealized losses presented by length of time
Less than 12 months, Fair Value		53,324
Less than 12 months, Unrealized Losses		(591)
12 months or longer, Fair Value		52,061
12 months or longer, Unrealized Losses		(1,247)
Total Fair Value		105,385
Total Unrealized Losses		$ (1,838)