Nature of Operations and Summary of Significant Accounting Policies - Allowance for Loan Losses (Details)	12 Months Ended
Dec. 31, 2017 USD ($) key_element
Accounting Policies [Abstract]
Number of key element used in assessing the appropriateness of the allowance for loan losses \| key_element	3
Commercial relationships threshold that exhibit credit weaknesses \| $	$ 500,000

Allowance for Loan Losses, Number Of Key Elements Applied to Determination Of Valuation Allowance

No definition available.

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