Fair value estimates - Carrying and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investment securities:
Available-for-sale	$ 275,050	$ 272,502
Common equity securities	278	46
Held-to-maturity	8,758	9,547
Loans held for sale		106
Mortgage servicing rights	724	728
Other assets	72,276	64,469
Carrying Value
Financial assets:
Cash and cash equivalents	35,379	37,488
Investment securities:
Available-for-sale	275,050	272,548
Common equity securities	278
Held-to-maturity	8,780	9,274
Loans held for sale		106
Net loans	1,733,816	1,674,105
Accrued interest receivable	6,802	6,936
Mortgage servicing rights	724	728
Restricted equity securities	11,356	8,562
Interest rate swaps	574	655
Total assets	2,072,759	2,010,402
Financial liabilities:
Deposits	1,718,861	1,719,018
Short-term borrowings	187,450	123,675
Long-term debt	48,911	49,734
Accrued interest payable	538	497
Interest rate swap	568	733
Total liabilities	1,956,328	1,893,657
Fair Value
Financial assets:
Cash and cash equivalents	35,379	37,488
Investment securities:
Available-for-sale	275,050	272,548
Common equity securities	278
Held-to-maturity	8,758	9,547
Loans held for sale		106
Net loans	1,688,615	1,645,292
Accrued interest receivable	6,802	6,936
Mortgage servicing rights	1,629	1,638
Restricted equity securities	11,356	8,562
Interest rate swaps	574	655
Total assets	2,028,441	1,982,772
Financial liabilities:
Deposits	1,714,013	1,666,284
Short-term borrowings	187,450	123,675
Long-term debt	49,032	50,147
Accrued interest payable	538	497
Interest rate swap	568	733
Total liabilities	1,951,601	1,841,336
Level 1
Financial assets:
Cash and cash equivalents	35,379	37,488
Investment securities:
Available-for-sale	25,347	19,860
Common equity securities	278
Level 2
Investment securities:
Available-for-sale	249,703	252,688
Held-to-maturity	8,758	9,547
Loans held for sale		106
Accrued interest receivable	6,802	6,936
Mortgage servicing rights	1,629	1,638
Restricted equity securities	11,356	8,562
Interest rate swaps	574	655
Financial liabilities:
Deposits	1,714,013	1,666,284
Short-term borrowings	187,450	123,675
Long-term debt	49,032	50,147
Accrued interest payable	538	497
Interest rate swap	568	733
Level 3
Investment securities:
Net loans	$ 1,688,615	$ 1,645,292

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents accrued interest payable as of the balance sheet date.

No definition available.