SECURITIES - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
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	0
Available for Sale, Fair Value, Due in less than one year	0
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	541
Available for Sale, Fair Value, Due after one year through five years	547
Held for Investment, Amortized Cost, Due after five years through ten years	0
Held for Investment, Fair Value, Due after five years through ten years	0
Available for Sale, Amortized Cost, Due after five years through ten years	8,083
Available for Sale, Fair Value, Due after five years through ten years	8,093
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	119,682
Available for Sale, Fair Value, Due after ten years	119,220
Held for Investment, Amortized Cost, Total	176,724	0
Held for Investment, Fair Value, Total	175,183
Available for Sale, Amortized Cost, Total	607,190	658,458
Available for Sale, Fair Value, Total	127,860
Gross Amortized Cost, Held for Investment Securities	176,724
Fair value, Held for Investment Securities	175,183
Gross Amortized Cost, Available for Sale	607,190	658,458
Fair Value, Available for Sale	601,541
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Total	87,148	129,468
Gross Amortized Cost, Held for Investment Securities	55,561
Fair value, Held for Investment Securities	55,406
Gross Amortized Cost, Available for Sale	87,148	129,468
Fair Value, Available for Sale	87,934
Collateralized Mortgage Obligations Of Us Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Total	290,647	383,392
Gross Amortized Cost, Held for Investment Securities	121,163
Fair value, Held for Investment Securities	119,777
Gross Amortized Cost, Available for Sale	290,647	383,392
Fair Value, Available for Sale	283,610
Private mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Total	29,922	29,800
Gross Amortized Cost, Held for Investment Securities	0
Fair value, Held for Investment Securities	0
Gross Amortized Cost, Available for Sale	29,922	29,800
Fair Value, Available for Sale	30,238
Private collateralized mortgage obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Total	71,167	76,520
Gross Amortized Cost, Held for Investment Securities	0
Fair value, Held for Investment Securities	0
Gross Amortized Cost, Available for Sale	71,167	76,520
Fair Value, Available for Sale	71,899
No Contractual Maturity [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Total	0
Gross Amortized Cost, Held for Investment Securities	0
Fair value, Held for Investment Securities	0
Gross Amortized Cost, Available for Sale	0
Fair Value, Available for Sale	$ 0