Acquisitions First Association Bank Acquisition - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 15, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 50,832	$ 22,950	$ 17,428
First Association Bank
Business Acquisition [Line Items]
Cash and cash equivalents	$ 167,663
Investment securities	222,391
Loans	26,422
Allowance for loan losses	0
Core deposit intangible	1,930
Other assets	5,823
Total assets acquired	424,229
Deposits	356,818
Bank loan	16,905
Deferred tax liability (asset)	3,918
Other liabilities	536
Total liabilities assumed	378,177
Excess of assets acquired over liabilities assumed	46,052
Consideration paid	57,906
Goodwill	11,854	$ 11,900
As initially reported | First Association Bank
Business Acquisition [Line Items]
Cash and cash equivalents	167,663
Investment securities	219,913
Loans	26,264
Allowance for loan losses	(224)
Core deposit intangible	0
Other assets	5,823
Total assets acquired	419,439
Deposits	356,737
Bank loan	16,905
Deferred tax liability (asset)	0
Other liabilities	536
Total liabilities assumed	374,178
Excess of assets acquired over liabilities assumed	45,261
Fair Value Adjustments | First Association Bank
Business Acquisition [Line Items]
Cash and cash equivalents	0
Investment securities	2,478
Loans	158
Allowance for loan losses	224
Core deposit intangible	1,930
Other assets	0
Total assets acquired	4,790
Deposits	81
Bank loan	0
Deferred tax liability (asset)	3,918
Other liabilities	0
Total liabilities assumed	3,999
Excess of assets acquired over liabilities assumed	$ 791