Cash, Dividend and Loan Restrictions - Additional Information (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash Dividend and Loan Restrictions [Line Items]
Average Reserve Balance Maintained With Federal Reserve Bank	$ 56.6	$ 75.4
Maximum Amount Available For Transfer Of Loans	41.8
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval	$ 59.0

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Article 4

Name:	us-gaap_StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant