Securities Held-to-Maturity - Schedule of Maturity Profile of Securities Held-to-Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity due one year through five years	$ 2,000
Held-to-maturity due five years through ten years	7,494	$ 7,521
Held-to-maturity due over ten years	7,369	12,659
Held-to-maturity cost or amortized cost	$ 16,863	$ 20,180