Loans and The Allowance for Loan Losses - Summary of Loan by Risk Rating (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 2,201,336	$ 2,203,810
Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,160,544	1,166,925
Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,205	9,896
Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,436	10,355
Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	247	250
Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,020,904	1,016,384
Consumer, Excluding Consumer Other Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,932,140	1,928,603
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	934,595	922,627
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	75,013	80,662
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	849,178	834,264
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,014	1,022
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	265	270
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	840,962	821,815
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,948	2,848
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,469	1,523
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,635	4,660
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,549	2,566
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,581	7,789
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	247	250
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	927,837	915,941
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	73,279	78,869
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	73,354	91,050
Consumer and Commercial Portfolio Segment | Loans rated 1 - 6 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	73,354	91,050
Consumer and Commercial Portfolio Segment | Loans rated 7 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 8 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 9 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 10 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans not rated | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	249,285	253,509
Commercial business | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	244,949	252,765
Commercial business | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,030	744
Commercial business | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	306	0
Commercial business | Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business | Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business | Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,911	21,698
Consumer | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	3
Consumer | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	123	121
Consumer | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer | Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer | Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer | Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 19,788	$ 21,574