Investment securities (Tables)

3 Months Ended

Mar. 31, 2017

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

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
March 31, 2017	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	20,050	$	1	$	156	$	19,895
U.S. Government-sponsored enterprises		83,677		72		1,277		82,472
State and municipals:
Taxable		14,663		604				15,267
Tax-exempt		105,894		2,104		461		107,537
Mortgage-backed securities:
U.S. Government agencies		19,321		47		36		19,332
U.S. Government-sponsored enterprises		20,213		46		118		20,141
Total	$	263,818	$	2,874	$	2,048	$	264,644
Held-to-maturity:
Tax-exempt state and municipals	$	6,861	$	86	$	83	$	6,864
Mortgage-backed securities:
U.S. Government agencies		64						64
U.S. Government-sponsored enterprises		3,255		176				3,431
Total	$	10,180	$	262	$	83	$	10,359

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2016	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	7,570			$	132	$	7,438
U.S. Government-sponsored enterprises		82,314	$	79		1,480		80,913
State and municipals:
Taxable		14,698		566		39		15,225
Tax-exempt		110,931		2,309		640		112,600
Mortgage-backed securities:
U.S. Government agencies		21,041		48		47		21,042
U.S. Government-sponsored enterprises		22,303		48		159		22,192
Total	$	258,857	$	3,050	$	2,497	$	259,410
Held-to-maturity:
Tax-exempt state and municipals	$	6,862	$	72	$	67	$	6,867
Mortgage-backed securities:
U.S. Government agencies		68		1				69
U.S. Government-sponsored enterprises		3,587		191				3,778
Total	$	10,517	$	264	$	67	$	10,714

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
March 31, 2017	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	17,411	$	156					$	17,411	$	156
U.S. Government-sponsored enterprises		62,591		1,277						62,591		1,277
State and municipals:
Taxable
Tax-exempt		51,467		544						51,467		544
Mortgage-backed securities:
U.S. Government agencies		5,769		23	$	1,337	$	13		7,106		36
U.S. Government-sponsored enterprises		13,832		66		2,380		52		16,212		118
Total	$	151,070	$	2,066	$	3,717	$	65	$	154,787	$	2,131

	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2016	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	7,438	$	132					$	7,438	$	132
U.S. Government-sponsored enterprises		59,460		1,480						59,460		1,480
State and municipals:
Taxable		1,035		39						1,035		39
Tax-exempt		55,166		707	$	226				55,392		707
Mortgage-backed securities:
U.S. Government agencies		5,917		27		1,496	$	20		7,413		47
U.S. Government-sponsored enterprises		16,412		85		2,712		74		19,124		159
Total	$	145,428	$	2,470	$	4,434	$	94	$	149,862	$	2,564

Available-for-Sale Securities

Maturity distribution of fair value

	Fair
March 31, 2017	Value
Within one year	$	39,613
After one but within five years		118,950
After five but within ten years		49,157
After ten years		17,451
		225,171
Mortgage-backed securities		39,473
Total	$	264,644

Held-to-maturity Securities

Maturity distribution of fair value

	Amortized		Fair
March 31, 2017	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,861	$	6,864
		6,861		6,864
Mortgage-backed securities		3,319		3,495
Total	$	10,180	$	10,359