Deposits - Narrative (Details) (Merger with CFS Bancorp, Inc. (Citizens), USD $) In Thousands, unless otherwise specified	Nov. 12, 2013
Merger with CFS Bancorp, Inc. (Citizens)
Business Acquisition [Line Items]
Percentage of Interest Acquired	100.00%
Deposits assumed	$ 955,432

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant