Dividend Limitations on Affiliate Bank Additional Information (Details) $ in Millions	Dec. 31, 2018 USD ($)
Disclosure Of Restrictions On Dividends Loans And Advances Disclosure [Abstract]
Aggregate amount of unrestricted funds available for dividend without prior regulatory approval	$ 9.2

Amount of dividends that can be declared or paid without approval of regulatory agency.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant