SECURITIES - Contractual Maturities of Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available for Sale, Amortized Cost
Amortized Cost, Within one year	$ 12,583
Amortized Cost, One through five years	79,099
Amortized Cost, Six through ten years	107,719
Amortized Cost, After ten years	169,412
Amortized Cost	1,002,803	$ 905,857
Fair Value, Within one year	12,715
Fair Value, One through five years	82,440
Fair Value, Six through ten years	111,782
Fair Value, After ten years	169,902
Fair Value	1,007,540	925,279
Parent Company
Available for Sale, Amortized Cost
Fair Value	130	149
U. S. government agency
Available for Sale, Amortized Cost
Amortized Cost	951	499
Fair Value	955	504
State and municipal
Available for Sale, Amortized Cost
Amortized Cost	361,335	332,999
Fair Value	369,286	350,733
Mortgage-backed securities-residential (Government Sponsored Entity)
Available for Sale, Amortized Cost
Amortized Cost, Debt securities without a single maturity date	450,006
Amortized Cost	450,006	332,525
Fair Value, Debt securities without a single maturity date	446,630
Fair Value	446,630	334,080
Collateralized mortgage obligations (Government Sponsored Entity)
Available for Sale, Amortized Cost
Amortized Cost, Debt securities without a single maturity date	179,314
Amortized Cost	179,314	228,621
Fair Value, Debt securities without a single maturity date	179,401
Fair Value	179,401	228,749
Equity securities
Available for Sale, Amortized Cost
Amortized Cost, Equity securities	4,670
Amortized Cost	4,670	4,689
Available-for-sale Securities, Equity Securities	4,670
Fair Value	$ 4,670	$ 4,689