Income Tax - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation Allowance [Line Items]
Tax expense applicable to security gains and losses, including unrealized losses relating to other-than-temporary charges	$ 435	$ 760	$ 157
Increase (decrease) in deferred tax assets	4,163
Valuation allowance	15,736	17,568	$ 17,171
Additional paid-in capital	504,530	$ 431,220
Unrecorded deferred tax liability	8,847
Merger with Ameriana Bancorp
Valuation Allowance [Line Items]
Increase (decrease) in deferred tax assets	9,262
Additional paid-in capital	11,883
Merger with CFS Bancorp, Inc.
Valuation Allowance [Line Items]
Additional paid-in capital	13,393
State and Local Jurisdiction
Valuation Allowance [Line Items]
Valuation allowance	15,736
State tax loss carryforward	121,626
Valuation allowance on state loss carryforward	120,369
Available for Sale Securities
Valuation Allowance [Line Items]
Decrease in deferred tax liability	955
Deferred Compensation
Valuation Allowance [Line Items]
Increase (decrease) in deferred tax assets	(857)
Loans
Valuation Allowance [Line Items]
Increase (decrease) in deferred tax assets	(1,873)
Operating Loss Carryforwards | Federal
Valuation Allowance [Line Items]
Increase (decrease) in deferred tax assets	(1,662)
Allowance for Loan Losses
Valuation Allowance [Line Items]
Increase (decrease) in deferred tax assets	$ (789)