SECURITIES - Amortized Cost and Fair Value of Securities Available for Sale and Held for Investment (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	$ 607,190	$ 658,458
Gross Unrealized Gains, Available for Sale	3,791	3,156
Gross Unrealized Losses, Available for Sale	(9,440)	(20,003)
Fair Value, Available for Sale	601,541	641,611
Gross Amortized Cost, Held for Investment Securities	176,724
Gross Unrealized Gains, Held for Investment Securities	53
Gross Unrealized Losses, Held for Investment Securities	(1,594)
Fair Value Held To Maturity	175,183
US Treasury Securities and obligations of US Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	100	100
Gross Unrealized Gains, Available for Sale	0	0
Gross Unrealized Losses, Available for Sale	0	0
Fair Value, Available for Sale	100	100
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	87,148	129,468
Gross Unrealized Gains, Available for Sale	1,433	1,456
Gross Unrealized Losses, Available for Sale	(647)	(4,189)
Fair Value, Available for Sale	87,934	126,735
Gross Amortized Cost, Held for Investment Securities	55,561
Gross Unrealized Gains, Held for Investment Securities	14
Gross Unrealized Losses, Held for Investment Securities	(169)
Fair Value Held To Maturity	55,406
Collateralized Mortgage Obligations Of Us Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	290,647	383,392
Gross Unrealized Gains, Available for Sale	560	776
Gross Unrealized Losses, Available for Sale	(7,597)	(14,747)
Fair Value, Available for Sale	283,610	369,421
Gross Amortized Cost, Held for Investment Securities	121,163
Gross Unrealized Gains, Held for Investment Securities	39
Gross Unrealized Losses, Held for Investment Securities	(1,425)
Fair Value Held To Maturity	119,777
Private mortgage backed securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	29,922	29,800
Gross Unrealized Gains, Available for Sale	316	0
Gross Unrealized Losses, Available for Sale	0	(226)
Fair Value, Available for Sale	30,238	29,574
Gross Amortized Cost, Held for Investment Securities	0
Fair Value Held To Maturity	0
Private collateralized mortgage obligations [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	71,167	76,520
Gross Unrealized Gains, Available for Sale	976	731
Gross Unrealized Losses, Available for Sale	(244)	(413)
Fair Value, Available for Sale	71,899	76,838
Gross Amortized Cost, Held for Investment Securities	0
Fair Value Held To Maturity	0
Collateralized Loan Obligations [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	122,440	32,592
Gross Unrealized Gains, Available for Sale	12	0
Gross Unrealized Losses, Available for Sale	(952)	(413)
Fair Value, Available for Sale	121,500	32,179
Obligations of state and political subdivisions [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	5,766	6,586
Gross Unrealized Gains, Available for Sale	494	193
Gross Unrealized Losses, Available for Sale	0	(15)
Fair Value, Available for Sale	$ 6,260	$ 6,764