Investment Securities (Tables)

3 Months Ended

Mar. 31, 2014

Investments Debt And Equity Securities [Abstract]

Amortized Cost and Estimated Fair Values of Investments in Debt and Equity Securities

The amortized cost and estimated fair values of investments in debt and equity securities are summarized in the following tables:

	March 31, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Securities Available for Sale
Obligations of U.S. government corporations and agencies	$	86,803	$	4,226	$	(242	)	$	90,787
Obligations of states and political subdivisions		4,489		76		—			4,565
Corporate debt securities		1,880		37		—			1,917
Total securities available for sale	$	93,172	$	4,339	$	(242	)	$	97,269
Securities Held to Maturity
Obligations of U.S. government corporations and agencies	$	331,892	$	1,327	$	(3,154	)	$	330,065
Obligations of states and political subdivisions		12,631		—		(730	)		11,901
Total securities held to maturity	$	344,523	$	1,327	$	(3,884	)	$	341,966

	December 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Securities Available for Sale
Obligations of U.S. government corporations and agencies	$	93,055	$	4,445	$	(357	)	$	97,143
Obligations of states and political subdivisions		5,513		77		(1	)		5,589
Corporate debt securities		1,877		38		—			1,915
Total securities available for sale	$	100,445	$	4,560	$	(358	)	$	104,647
Securities Held to Maturity
Obligations of U.S. government corporations and agencies	$	227,864	$	298	$	(5,540	)	$	222,622
Obligations of states and political subdivisions		12,640		—		(1,455	)		11,185
Total securities held to maturity	$	240,504	$	298	$	(6,995	)	$	233,807

Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity

For purposes of the following table, the entire outstanding balance of these mortgage-backed securities issued by U.S. government corporations and agencies is categorized based on final maturity date. 

Investment Securities	Available for Sale				Held to Maturity
(In thousands)	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year	$	408	$	432		—		—
Due after one year through five years		3,407		3,520		—		—
Due after five years through ten years		30,236		31,182		—		—
Due after ten years		59,121		62,135	$	344,523	$	341,966
Totals	$	93,172	$	97,269	$	344,523	$	341,966

Gross Unrealized Losses on Investment

Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows:

	Less than 12 months					12 months or more				Total
March 31, 2014	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
	(in thousands)
Securities available for sale:
Obligations of U.S. government corporations and agencies	$	10,156	$	(242	)		—		—	$	10,156	$	(242	)
Obligations of states and political subdivisions		—		—			—		—		—		—
Corporate debt securities		—		—			—		—		—		—
Total securities available for sale	$	10,156	$	(242	)		—		—	$	10,156	$	(242	)
Securities held to maturity:
Obligations of U.S. government corporations and agencies	$	163,349	$	(3,154	)		—		—	$	163,349	$	(3,154	)
Obligations of states and political subdivisions		11,901		(730	)		—		—		11,901		(730	)
Total securities held to maturity	$	175,250	$	(3,884	)		—		—	$	175,250	$	(3,884	)

	Less than 12 months					12 months or more				Total
December 31, 2013	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
	(in thousands)
Securities available for sale:
Obligations of U.S. government corporations and agencies	$	10,287	$	(357	)		—		—	$	10,287	$	(357	)
Obligations of states and political subdivisions		199		(1	)		—		—		199		(1	)
Corporate debt securities		—		—			—		—		—		—
Total securities available for sale	$	10,486	$	(358	)		—		—	$	10,486	$	(358	)
Securities held to maturity:
Obligations of U.S. government corporations and agencies	$	188,218	$	(5,540	)		—		—	$	188,218	$	(5,540	)
Obligations of states and political subdivisions		11,185		(1,455	)		—		—		11,185		(1,455	)
Total securities held to maturity	$	199,403	$	(6,995	)		—		—	$	199,403	$	(6,995	)