Investment in Securities (Tables)

3 Months Ended

Mar. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of Investment Securities

The amortized cost, gross unrealized gains, gross unrealized losses and fair value of investment securities are summarized as follows:

	March 31, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized
(In thousands)	Cost		Gains		Losses		Fair Value
State and political subdivisions	$	327,139	$	8,585	$	181	$	335,543
U.S. government agencies		104,273		198		820		103,651
Certificates of deposit		1,995		—		—		1,995
Total	$	433,407	$	8,783	$	1,001	$	441,189
	December 31, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized
(In thousands)	Cost		Gains		Losses		Fair Value
State and political subdivisions	$	332,732	$	3,791	$	1,806	$	334,717
U.S. government agencies		106,153		86		1,417		104,822
Certificates of deposit		1,995		—		—		1,995
Total	$	440,880	$	3,877	$	3,223	$	441,534

Schedule of the Fair Value of Securities with Unrealized Losses

The fair values of securities with unrealized losses are as follows:

	March 31, 2019
	Less than 12 months				12 months or more				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
(In thousands)	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
State and political subdivisions	$	—	$	—	$	22,617	$	181	$	22,617	$	181
U.S. government agencies		4,945		5		44,251		815		49,196		820
Certificates of deposit		—		—		—		—		—		—
Total	$	4,945	$	5	$	66,868	$	996	$	71,813	$	1,001
	December 31, 2018
	Less than 12 months				12 months or more				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
(In thousands)	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
State and political subdivisions	$	91,248	$	556	$	60,546	$	1,250	$	151,794	$	1,806
U.S. government agencies		30,409		130		38,005		1,287		68,414		1,417
Certificates of deposit		—		—		—		—		—		—
Total	$	121,657	$	686	$	98,551	$	2,537	$	220,208	$	3,223

Schedule of Amortized Cost and Fair Value of Investment

The amortized cost and fair value of investment securities by contractual maturity are shown in the following table. Expected maturities may differ from contractual maturities because borrowers have the right to prepay obligations with or without prepayment penalties.

	March 31, 2019
(In thousands)	Amortized Cost		Fair Value
Due in 1 year or less	$	17,585	$	17,607
Due after 1 year through 5 years		123,001		124,343
Due after 5 years through 10 years		241,321		248,393
Due after 10 years		51,500		50,846
Total	$	433,407	$	441,189