SECURITIES - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	$ 198,231	$ 203,525
Held for Investment, Fair Value, Total	198,820	202,813
Available for Sale, Amortized Cost, Total	905,295
Available for Sale, Fair Value, Total	905,182	790,766
Collateralized Loan Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Due in less than one year	0
Held for Investment, Fair Value, Due in less than one year	0
Available for Sale Amortized Cost, Due in less than one year	4,779
Available for Sale, Fair Value, Due in less than one year	4,853
Held for Investment, Amortized Cost, Due after one year through five years	0
Held for Investment, Fair Value, Due after one year through five years	0
Available for Sale, Amortized Cost, Due after one year through five years	73,041
Available for Sale, Fair Value, Due after one year through five years	72,962
Held for Investment, Amortized Cost, Due after five years through ten years	41,389
Held for Investment, Fair Value, Due after five years through ten years	37,536
Available for Sale, Amortized Cost, Due after five years through ten years	119,832
Available for Sale, Fair Value, Due after five years through ten years	117,893
Held for Investment, Amortized Cost, Due after ten years	0
Held for Investment, Fair Value, Due after ten years	0
Available for Sale, Amortized Cost, Due after ten years	35,545
Available for Sale, Fair Value, Due after ten years	36,416
Held for Investment, Amortized Cost, Total	41,389
Held for Investment, Fair Value, Total	37,536
Available for Sale, Amortized Cost, Total	233,197
Available for Sale, Fair Value, Total	232,124
Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	64,718
Held for Investment, Fair Value, Total	67,420	65,551
Available for Sale, Amortized Cost, Total	206,630
Available for Sale, Fair Value, Total	209,136	191,749
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	84,346
Held for Investment, Fair Value, Total	86,236	89,440
Available for Sale, Amortized Cost, Total	297,383
Available for Sale, Fair Value, Total	297,834	238,190
Private mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	0
Held for Investment, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	32,610
Available for Sale, Fair Value, Total	31,612	31,792
Private collateralized mortgage obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	7,778
Held for Investment, Fair Value, Total	7,628	7,882
Available for Sale, Amortized Cost, Total	82,940
Available for Sale, Fair Value, Total	82,258	77,957
Corporate and other debt securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	0
Held for Investment, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	8,764
Available for Sale, Fair Value, Total	46,172	44,273
Private commercial mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	0
Held for Investment, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	43,771
Available for Sale, Fair Value, Total	$ 43,484	$ 40,420