Core Deposit and Other Intangibles - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Measurement period adjustment	$ 2,142
Ameriana
Finite-Lived Intangible Assets [Line Items]
Measurement period adjustment	$ 2,142

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration