New Authoritative Accounting Guidance - Narrative (Details) (New Accounting Pronouncement, Early Adoption, Effect, USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014
New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncement, Early Adoption [Line Items]
Decrease in other noninterest expense	$ 0.9
Increase in income tax expense	$ 0.9

The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes, and in deferred and other tax liabilities and assets.

No definition available.

Name:	us-gaap_IncreaseDecreaseInIncomeTaxes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration