Loans Receivable - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	$ 10,973	$ 10,909
Nonaccrual originated loans guaranteed by governmental agencies	1,600	2,800
Commercial Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	8,679	8,580
Commercial Business | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	3,613	3,531
Commercial Business | Owner-occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	3,795	3,728
Commercial Business | Non-owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	1,271	1,321
One-to-four Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	87	94
Real Estate Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	2,008	2,008
Real Estate Construction and Land Development | One-to-four Family Real Estate Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	2,008	2,008
Real Estate Construction and Land Development | Five or More Family Residential and Commercial Properties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	$ 199	$ 227