SECURITIES - Amortized Cost and Fair Value of Securities Available for Sale and Held for Investment (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	$ 765,390	$ 746,390
Gross Unrealized Gains, Available for Sale	4,260	4,388
Gross Unrealized Losses, Available for Sale	(7,564)	(9,403)
Fair Value, Available for Sale	762,086	741,375
Gross Amortized Cost, Held for Investment Securities	214,777	207,904
Gross Unrealized Gains, Held for Investment Securities	1,830	1,507
Gross Unrealized Losses, Held for Investment Securities	(431)	(623)
Held for investment fair value	216,176	208,788
U.S. Treasury Securities and obligations of U.S. Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	3,775	3,876
Gross Unrealized Gains, Available for Sale	68	23
Gross Unrealized Losses, Available for Sale	0	0
Fair Value, Available for Sale	3,843	3,899
Mortgage-backed Securities, 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	121,924	123,981
Gross Unrealized Gains, Available for Sale	1,531	1,501
Gross Unrealized Losses, Available for Sale	(758)	(423)
Fair Value, Available for Sale	122,697	125,059
Gross Amortized Cost, Held for Investment Securities	66,056	67,535
Gross Unrealized Gains, Held for Investment Securities	708	812
Gross Unrealized Losses, Held for Investment Securities	(24)	0
Held for investment fair value	66,740	68,347
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	313,082	352,483
Gross Unrealized Gains, Available for Sale	989	1,075
Gross Unrealized Losses, Available for Sale	(4,497)	(6,077)
Fair Value, Available for Sale	309,574	347,481
Gross Amortized Cost, Held for Investment Securities	98,857	114,541
Gross Unrealized Gains, Held for Investment Securities	751	695
Gross Unrealized Losses, Held for Investment Securities	(307)	(280)
Held for investment fair value	99,301	114,956
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	124,462	29,967
Gross Unrealized Gains, Available for Sale	253	291
Gross Unrealized Losses, Available for Sale	(474)	0
Fair Value, Available for Sale	124,241	30,258
Gross Amortized Cost, Held for Investment Securities	0
Held for investment fair value	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	32,448	85,175
Gross Unrealized Gains, Available for Sale	32	688
Gross Unrealized Losses, Available for Sale	(304)	(728)
Fair Value, Available for Sale	32,176	85,135
Gross Amortized Cost, Held for Investment Securities	8,564
Gross Unrealized Gains, Held for Investment Securities	0
Gross Unrealized Losses, Held for Investment Securities	0
Held for investment fair value	8,564
Collateralized loan obligations [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	94,260	127,397
Gross Unrealized Gains, Available for Sale	841	0
Gross Unrealized Losses, Available for Sale	(987)	(2,172)
Fair Value, Available for Sale	94,114	125,225
Gross Amortized Cost, Held for Investment Securities	41,300	25,828
Gross Unrealized Gains, Held for Investment Securities	371	0
Gross Unrealized Losses, Held for Investment Securities	(100)	(343)
Held for investment fair value	41,571	25,485
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	22,636	23,511
Gross Unrealized Gains, Available for Sale	513	810
Gross Unrealized Losses, Available for Sale	(276)	(3)
Fair Value, Available for Sale	22,873	$ 24,318
Corporate and other debt securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	32,171
Gross Unrealized Gains, Available for Sale	21
Gross Unrealized Losses, Available for Sale	(211)
Fair Value, Available for Sale	31,981
Gross Amortized Cost, Held for Investment Securities	0
Held for investment fair value	0
Private commercial mortgage backed securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	20,632
Gross Unrealized Gains, Available for Sale	12
Gross Unrealized Losses, Available for Sale	(57)
Fair Value, Available for Sale	20,587
Gross Amortized Cost, Held for Investment Securities	0
Held for investment fair value	0
Other [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Held for Investment Securities	0
Gross Unrealized Gains, Held for Investment Securities	0
Gross Unrealized Losses, Held for Investment Securities	0
Held for investment fair value	$ 0