Goodwill - Narrative (Details) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Nov. 12, 2013 Merger with CFS Bancorp, Inc. (Citizens)
Business Acquisition [Line Items]
Percentage of Interest Acquired			100.00%
Goodwill acquired	$ 47,573,000	$ 18,000
Goodwill impairment loss	$ 0	$ 0

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

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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