Federal Bank Stocks - (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Federal Home Loan Bank stock	$ 3.3	$ 3.6
Federal Reserve Bank stock	$ 1.3	$ 1.3

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).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6478792&loc=d3e63345-112809

Name:	us-gaap_FederalReserveBankStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant