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Other Real Estate Owned (Details) - USD ($) $ in Thousands	6 Months Ended
Other Real Estate Owned (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Real Estate Properties [Line Items]
Advances from Federal Home Loan Banks			$ 175,200
Mortgage Loans in Process of Foreclosure, Amount	$ 22,800		$ 22,000
Total
Beginning balance	48,030	$ 51,097
Additions	7,894	11,868
Sales	(11,012)	(15,769)
Write-downs	(2,289)	(2,698)
Ending balance	46,236	46,633
Mortgage
Total
Beginning balance	17,200
Ending balance	17,700
2019 Acquisitions
Total
Additions	3,613
HomeBancorp Inc.
Total
Additions		$ 2,135
Federal Home Loan Bank of Chicago
Real Estate Properties [Line Items]
Advances from Federal Home Loan Banks	$ 13,500