Investment Securities (Tables)

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Reconciliation of Available-for-Sale Securities

	June 30, 2018									December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)									(in thousands)
AVAILABLE FOR SALE
U.S. Treasury and U.S. government agencies	$	149,859	$	—	$	(3,514	)	$	146,345	$	148,968	$	78	$	(1,791	)	$	147,255
Mortgage-backed securities, residential	404,880		105		(12,270		)	392,715		419,538		479		(5,763		)	414,254
Mortgage-backed securities, multifamily	13,181		—		(307		)	12,874		10,133		7		(63		)	10,077
Obligations of states and political subdivisions	49,898		167		(843		)	49,222		51,289		448		(417		)	51,320
Debt securities	5,000		75		—			5,075		5,000		140		—			5,140
	$	622,818	$	347	$	(16,934	)	$	606,231	$	634,928	$	1,152	$	(8,034	)	$	628,046

Reconciliation of Held-to-Maturity Securities

	June 30, 2018									December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)									(in thousands)
HELD TO MATURITY
U.S. government agencies	$	38,437	$	—	$	(943	)	$	37,494	$	33,415	$	24	$	(402	)	$	33,037
Mortgage-backed securities, residential	73,538		127		(2,355		)	71,310		54,991		249		(978		)	54,262
Mortgage-backed securities, multifamily	1,905		—		(56		)	1,849		1,957		—		(22		)	1,935
Obligations of states and political subdivisions	39,452		133		(421		)	39,164		43,318		306		(188		)	43,436
Debt securities	5,500		—		(1		)	5,499		6,004		14		—			6,018
	$	158,832	$	260	$	(3,776	)	$	155,316	$	139,685	$	593	$	(1,590	)	$	138,688

Summary of Investment Securities by Stated Maturity

The following table shows investment securities by stated maturity. Securities backed by mortgages have expected maturities that differ from contractual maturities because borrowers have the right to call or prepay, and are, therefore, classified separately with no specific maturity date (in thousands):

	Available for Sale				Held to Maturity
June 30, 2018	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	21,258	$	21,170	$	13,063	$	13,074
Due after one year through five years	114,026		111,549		41,523		40,979
Due after five years through ten years	41,818		40,686		25,533		24,926
Due after ten years	27,655		27,237		3,270		3,178
	204,757		200,642		83,389		82,157
Mortgage-backed securities	418,061		405,589		75,443		73,159
Total securities	$	622,818	$	606,231	$	158,832	$	155,316

Summary of Proceeds from Sales of Securities and Gross Gains and Losses on Sales of Securities

The following table shows proceeds from sales of securities and gross gains and losses on sales of securities for the periods indicated (in thousands):

	For the Three Months Ended June 30,					For the Six Months Ended June 30,
	2018		2017			2018		2017
Sale proceeds	$	—	$	—		$	—	$	4,499
Gross gains	—		—			—		2,539
Gross losses	—		(15		)	—		(15		)

Reconciliation of Available-for-Sale and Held-to-Maturity Securities in Continuous Unrealized Loss Position

The following table indicates the length of time individual securities have been in a continuous unrealized loss position for the periods presented:

	Less Than 12 Months				12 Months or Longer				Total
June 30, 2018	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Number of Securities	Fair Value		Unrealized Losses
	(dollars in thousands)
AVAILABLE FOR SALE
U.S. Treasury and U.S. government agencies	$	92,272	$	1,781	$	54,073	$	1,733	28	$	146,345	$	3,514
Mortgage-backed securities, residential	213,396		5,296		161,111		6,974		142	374,507		12,270
Mortgage-backed securities, multifamily	7,872		189		5,002		118		3	12,874		307
Obligations of states and political subdivisions	20,367		265		12,656		578		60	33,023		843
	$	333,907	$	7,531	$	232,842	$	9,403	233	$	566,749	$	16,934
HELD TO MATURITY
U.S. government agencies	$	30,948	$	464	$	6,546	$	479	7	$	37,494	$	943
Mortgage-backed securities, residential	45,533		1,302		19,894		1,053		35	65,427		2,355
Mortgage-backed securities, multifamily	1,849		56		—		—		2	1,849		56
Obligations of states and political subdivisions	15,394		199		5,894		222		33	21,288		421
Debt securities	4,000		1		—		—		1	4,000		1
	$	97,724	$	2,022	$	32,334	$	1,754	78	$	130,058	$	3,776

	Less Than 12 Months				12 Months or Longer				Total
December 31, 2017	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Number of Securities	Fair Value		Unrealized Losses
	(dollars in thousands)
AVAILABLE FOR SALE
U.S. Treasury and U.S. government agencies	$	80,391	$	646	$	54,769	$	1,145	27	$	135,160	$	1,791
Mortgage-backed securities, residential	199,387		1,723		157,739		4,040		118	357,126		5,763
Mortgage-backed securities, multifamily	—		—		5,088		63		1	5,088		63
Obligations of states and political subdivisions	9,612		77		12,970		340		39	22,582		417
	$	289,390	$	2,446	$	230,566	$	5,588	185	$	519,956	$	8,034
HELD TO MATURITY
U.S. government agencies	$	15,371	$	95	$	6,720	$	307	4	$	22,091	$	402
Mortgage-backed securities, residential	26,090		426		19,203		552		25	45,293		978
Mortgage-backed securities, multifamily	1,935		22		—		—		2	1,935		22
Obligations of states and political subdivisions	15,353		56		6,028		132		23	21,381		188
	$	58,749	$	599	$	31,951	$	991	54	$	90,700	$	1,590