Investment securities (Tables)

9 Months Ended

Sep. 30, 2016

Amortized cost and fair value of investment securities aggregated by investment category

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
September 30, 2016	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Government-sponsored enterprises	$	67,478	$	218	$	40	$	67,656
State and municipals:
Taxable		14,732		1,023		1		15,754
Tax-exempt		114,699		3,601		3		118,297
Mortgage-backed securities:
U.S. Government agencies		23,300		104		23		23,381
U.S. Government-sponsored enterprises		24,731		156		62		24,825
Total	$	244,940	$	5,102	$	129	$	249,913
Held-to-maturity:
Tax-exempt state and municipals	$	6,863	$	424	$		$	7,287
Mortgage-backed securities:
U.S. Government agencies		72		1				73
U.S. Government-sponsored enterprises		3,929		257				4,186
Total	$	10,864	$	682	$		$	11,546

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2015	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	10,030			$	31	$	9,999
U.S. Government-sponsored enterprises		68,831	$	291		62		69,060
State and municipals:
Taxable		15,842		735		32		16,545
Tax-exempt		121,099		3,915		90		124,924
Mortgage-backed securities:
U.S. Government agencies		31,612		73		117		31,568
U.S. Government-sponsored enterprises		32,928		119		208		32,839
Total	$	280,342	$	5,133	$	540	$	284,935
Held-to-maturity:
Tax-exempt state and municipals	$	6,865	$	186	$	16	$	7,035
Mortgage-backed securities:
U.S. Government agencies		84		1				85
U.S. Government-sponsored enterprises		5,160		326				5,486
Total	$	12,109	$	513	$	16	$	12,606

Fair value and unrealized losses of investment securities in continuous unrealized loss position

	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
September 30, 2016	Value		Losses		Value		Losses		Value		Losses
U.S. Government-sponsored enterprises	$	19,368	$	40					$	19,368	$	40
State and municipals:
Taxable		558		1						558		1
Tax-exempt		3,244		2	$	632	$	1		3,876		3
Mortgage-backed securities:
U.S. Government agencies		7,554		8		1,675		15		9,229		23
U.S. Government-sponsored enterprises		2,359		3		2,478		59		4,837		62
Total	$	33,083	$	54	$	4,785	$	75	$	37,868	$	129

	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2015	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	9,999	$	31					$	9,999	$	31
U.S. Government-sponsored enterprises		34,159		62						34,159		62
State and municipals:
Taxable					$	532	$	32		532		32
Tax-exempt		21,341		87		1,952		19		23,293		106
Mortgage-backed securities:
U.S. Government agencies		15,114		56		5,477		61		20,591		117
U.S. Government-sponsored enterprises		17,647		104		6,030		104		23,677		208
Total	$	98,260	$	340	$	13,991	$	216	$	112,251	$	556

Available-for-Sale Securities

Maturity distribution of fair value

	Fair
September 30, 2016	Value
Within one year	$	34,959
After one but within five years		90,493
After five but within ten years		49,407
After ten years		26,848
		201,707
Mortgage-backed securities		48,206
Total	$	249,913

Held-to-maturity Securities

Maturity distribution of fair value

	Amortized		Fair
September 30, 2016	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,863	$	7,287
		6,863		7,287
Mortgage-backed securities		4,001		4,259
Total	$	10,864	$	11,546