INVESTMENTS (Amortized Cost and Estimated Fair Values of investment securities Available-For-Sale by Contractual Maturity) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 57,794	$ 63,482
Due after one year through five years	283,422	277,297
Due after five years through ten years	190,435	212,825
Due after ten years	394,470	392,136
Total debt securities available for sale	926,121	945,740
Estimated Fair Value
Due in one year or less	58,089	63,747
Due after one year through five years	284,235	276,830
Due after five years through ten years	191,473	210,386
Due after ten years	392,165	385,804
Estimated Fair Value	$ 925,962	$ 936,767

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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