INVESTMENT SECURITIES, Amortized Cost, Maturities and Approximate Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Amortized Cost [Abstract]
Due in one year or less	$ 21,600
Due from one to five years	134,975
Due from five to ten years	87,559
Total securities available for sale	244,134		$ 244,706
Fair Value [Abstract]
Due in one year or less	21,838
Due from one to five years	139,088
Due from five to ten years	88,337
Total securities available for sale	249,263		247,099
Amortized Cost [Abstract]
Due in one year or less	836
Due from one to five years	4,191
Due from five to ten years	23,667
Due after ten years	18,447
Amortized Cost	47,141		61,309
Fair Value [Abstract]
Due in one year or less	843
Due from one to five years	4,405
Due from five to ten years	24,578
Due after ten years	19,794
Total securities held to maturity	49,620		63,272
Total Amortized Cost	291,275		306,015
Total Fair Value	298,883		310,371
Contingent liability from counterparty estimated future exposure from Visa litigation	752		752
Approximate cash payment per quarter for Visa litigation	74	$ 70
US Government agency securities held as available-for-sale pledged as collateral	$ 3,000		$ 3,000
Shares of Visa Class B securities held (in shares)	38,638		38,638