Loans Receivable and Allowance for Loan Losses - Summary of Loans Modified in Troubled Debt Restructurings and Related Recorded Investment (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($) Loan	Mar. 31, 2017 USD ($) Loan
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loan	9	21
Recorded Investment \| $	$ 322	$ 1,203
Commercial and industrial (including owner occupied commercial real estate)
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loan	0	1
Recorded Investment \| $	$ 0	$ 348
Manufactured housing
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loan	9	20
Recorded Investment \| $	$ 322	$ 855

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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