Investment Securities - Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank (FHLB) stock	$ 107,122	$ 95,213
Federal Reserve Bank Stock	85,630	85,630
CRA and Community Development Investment Funds	1,914	1,884
Other Investments	13,864	9,709
Marketable Securities	$ 208,530	$ 192,436

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
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Federal Reserve Bank stock represents an equity interest in the Federal Reserve Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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- References

No definition available.

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Amount of investment in marketable security.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
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Amount of investments classified as other.

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-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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