INVESTMENTS (Amortized Cost and Estimated Fair Values of investment securities Available-For-Sale by Contractual Maturity) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Amortized Cost
Due in one year or less	$ 6,554	$ 301
Due after one year through five years	169,896	157,710
Due after five years through ten years	204,061	168,136
Due after ten years	254,328	253,792
Total debt securities available for sale	634,839	579,939
Estimated Fair Value
Due in one year or less	6,631	306
Due after one year through five years	177,379	160,257
Due after five years through ten years	211,554	174,677
Due after ten years	258,855	255,586
Estimated Fair Value	$ 654,419	$ 590,826