SECURITIES - Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized Cost
Over one year through five years	$ 1,606
Over five years through ten years	8,959
Over ten years	224,663
Amortized Cost	538,980	$ 648,230
Fair Value
Over one year through five years	1,642
Over five years through ten years	8,821
Over ten years	220,395
Total	543,225	652,132
Mortgage-backed securities: residential
Amortized Cost
Mortgage-backed securities	286,307
Amortized Cost	286,307	374,923
Fair Value
Mortgage-backed securities	294,672
Total	294,672	375,943
Mortgage-backed securities: commercial
Amortized Cost
Mortgage-backed securities	17,445
Amortized Cost	17,445	17,858
Fair Value
Mortgage-backed securities	17,695
Total	$ 17,695	$ 17,780

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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