Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2020
Accounting Policies [Abstract]
Interest bearing amounts held at other financial institutions	$ 22.7	$ 30.6
Dilutive effect of common stock issuable upon exercise of options	286,418
Anti-dilutive shares	123,384

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 28A
-URI http://asc.fasb.org/extlink&oid=117326831&loc=d3e1500-109256

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Balance Type:	na
Period Type:	duration