Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	$ 17,292	$ 17,292	$ 22,128
Loans with a specific valuation allowance, Unpaid principal balance	17,949	17,949	22,374
Specific valuation allowance	3,081	3,081	6,881
Loans with a specific valuation allowance, Average balance	18,585	19,766	26,745
Loans without a specific valuation allowance, Recorded balance	109,124	109,124	108,135
Loans without a specific valuation allowance, Unpaid principal balance	131,490	131,490	131,059
Loans without a specific valuation allowance, Average balance	112,166	110,822	108,827
Recorded balance	126,416	126,416	130,263
Unpaid principal balance	149,439	149,439	153,433
Average balance	130,751	130,588	135,572
Residential Real Estate | Residential Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	2,890	2,890	2,759
Loans with a specific valuation allowance, Unpaid principal balance	2,998	2,998	2,825
Specific valuation allowance	297	297	856
Loans with a specific valuation allowance, Average balance	2,891	2,847	4,942
Loans without a specific valuation allowance, Recorded balance	10,449	10,449	8,853
Loans without a specific valuation allowance, Unpaid principal balance	11,344	11,344	9,925
Loans without a specific valuation allowance, Average balance	10,303	9,819	12,858
Recorded balance	13,339	13,339	11,612
Unpaid principal balance	14,342	14,342	12,750
Average balance	13,194	12,666	17,800
Commercial | Commercial Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	5,026	5,026	9,129
Loans with a specific valuation allowance, Unpaid principal balance	5,338	5,338	9,130
Specific valuation allowance	784	784	922
Loans with a specific valuation allowance, Average balance	5,152	6,478	10,441
Loans without a specific valuation allowance, Recorded balance	78,671	78,671	76,505
Loans without a specific valuation allowance, Unpaid principal balance	97,184	97,184	94,180
Loans without a specific valuation allowance, Average balance	79,422	78,450	72,323
Recorded balance	83,697	83,697	85,634
Unpaid principal balance	102,522	102,522	103,310
Average balance	84,574	84,928	82,764
Commercial | Other Commercial
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	7,501	7,501	8,814
Loans with a specific valuation allowance, Unpaid principal balance	7,646	7,646	8,929
Specific valuation allowance	1,189	1,189	4,419
Loans with a specific valuation allowance, Average balance	8,777	8,789	9,840
Loans without a specific valuation allowance, Recorded balance	14,042	14,042	15,136
Loans without a specific valuation allowance, Unpaid principal balance	16,354	16,354	17,724
Loans without a specific valuation allowance, Average balance	15,519	15,392	15,537
Recorded balance	21,543	21,543	23,950
Unpaid principal balance	24,000	24,000	26,653
Average balance	24,296	24,181	25,377
Consumer and Other | Home Equity
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	391	391	334
Loans with a specific valuation allowance, Unpaid principal balance	453	453	345
Specific valuation allowance	143	143	296
Loans with a specific valuation allowance, Average balance	469	424	257
Loans without a specific valuation allowance, Recorded balance	4,335	4,335	5,600
Loans without a specific valuation allowance, Unpaid principal balance	4,906	4,906	7,120
Loans without a specific valuation allowance, Average balance	5,119	5,279	6,004
Recorded balance	4,726	4,726	5,934
Unpaid principal balance	5,359	5,359	7,465
Average balance	5,588	5,703	6,261
Consumer and Other | Other Consumer
Summary of the impaired loans by portfolio class of loans
Loans with a specific valuation allowance, Recorded balance	1,484	1,484	1,092
Loans with a specific valuation allowance, Unpaid principal balance	1,514	1,514	1,145
Specific valuation allowance	668	668	388
Loans with a specific valuation allowance, Average balance	1,296	1,228	1,265
Loans without a specific valuation allowance, Recorded balance	1,627	1,627	2,041
Loans without a specific valuation allowance, Unpaid principal balance	1,702	1,702	2,110
Loans without a specific valuation allowance, Average balance	1,803	1,882	2,105
Recorded balance	3,111	3,111	3,133
Unpaid principal balance	3,216	3,216	3,255
Average balance	$ 3,099	$ 3,110	$ 3,370